VERSUS Part 3: San Diego Padres vs. Los Angeles Dodgers

Editor's Note: Most of my baseball-related posts here at "Solvent is So Yesterday" have thus far focused on comparing teams across specific dimensions of baseball talent (e.g. hitting, fielding, and pitching). This method of presenting the data provides a lot of utility in explicating exactly what a team does well or not so well, but it also limits our ability to view teams at a holistic level. For example, the numbers indicate that the Red Sox will be strong on offense and in the rotation, but weak on defense and in relief. How good a team does that make them?

Like any good analyst, we need an alternate window into the data, different ways to mix and match the data. With that in mind, I think it is interesting to compare two teams across all the dimensions we have thus far studied, to get an idea of relative strength. The compared teams have been linked to each other, either by related characteristics or because they have a direct competition with each other.

In this, the final of a planned three part series, I compare the fortunes of the Los Angeles Dodgers and the San Diego Padres, who have generally been chosen by preseason analysts as the top two teams in the NL West.

Background
The Dodgers and Padres finished 2006 tied atop the weak NL West, each team winning 88 games on their ways to the playoffs. These SoCal rivals have taken the last three division titles between them (the Dodgers of the magical 2004 DePodesta season, and the Padres both in 2005 and 2006), and both teams have made the playoffs two of the last three years. Tradesports.com (a decent proxy for conventional wisdom) gives the Dodgers a 35% chance of winning the division and the Padres 25%, making these two teams the favorites for the division title in 2007. ESPN Sports Nation (another proxy for conventional wisdom) ranked the Dodgers as the 7th best MLB team, and the Padres the 15th best. In short, the conventional wisdom is that both of these teams will contend for the division crown, with many seeing the Dodgers as the superior team.

Competitive Landscape
In order to reach the playoffs, what types of hurdles will these teams have to clear? The road to the playoffs in the NL is much easier than the AL road. Beyond the Cardinals, there are no teams that look like extremely strong bets to make the playoffs. The wildcard could certainly come from the NL West, as it did in 2006. The Dodgers and Padres will also have to watch out for Arizona, who seem much improved and have a good chance to challenge for the wildcard or division.


Offense
Taking the projections from my NL Lineup Preview, the starting line-ups compare as follow:

Los Angeles Dodgers: 4.59 RPG
San Diego Padres: 5.04 RPG

I had to say I was amazed at the magnitude of the difference between these two teams. Did I somehow reverse the numbers? The Dodgers finished fourth in the NL in scoring last season (5.06 RPG) despite a pitching friendly park. The Padres, by contrast, finished 13th in the league with 4.51 RPG. What gives? Well, to first address the predicted collapse of the Dodger's offense, one has to consider a number of factors:

1. The loss of J.D. Drew. Yes, he is injury prone. Yes, he believes in the healing power of crystals. Nonetheless, Drew appeared in 146 games with the Dodgers, last year, and put up a .980 OPS. Replacing him this year will be a rapidly aging Luis Gonzalez.
2. The Dodgers got a number of surprisingly good performances from youngsters and vets in part-time roles last year, performances that are unlikely to be matched again this year. Andre Ethier, Jose Cruz Jr., Olmedo Saenz, Kenny Lofton, Bill Mueller, and James Loney all put up very good numbers in limited time. Certainly this speaks to the Dodgers unique depth last year. That sort of depth is difficult to retain on a long-term basis, and the Dodgers will likely suffer from the loss or regression of many of those players next year.
3. Juan Pierre. The suckiness of Juan Pierre can not be overstated.

The 2006 Padres offense was in many ways the polar opposite of the Dodgers, in which they suffered injury (Khalil Greene) and poor performance (Vinny Castilla) of many starters, and got generally atrocious bench contributions (World Series hero Mark Bellhorn). Thus, despite the obvious superiority of the Dodgers' offense last year, I expect a role reversal this year.

Comparing the benches, while recognizing that bench composition is still a relative unknown at this point:

Los Angeles Dodgers

Name	PECOTA (EqBA/EqOBP/EqSLG)
Mike Lieberthal	.267/.320/.416
James Loney	.296/.350/.473
Ramon Martinez	.268/.324/.368
Matt Kemp	.297/.345/.509
Jason Repko	.264/.325/.436

San Diego Padres

Name	PECOTA (EqBA/EqOBP/EqSLG)
Rob Bowen	.237/.324/.391
Russell Branyan	.245/.349/.516
Geoff Blum	.247/.304/.387
Jose Cruz Jr.	.251/.358/.457
Todd Walker	.275/.348/.415

Both benches are amongst the best in the NL. A weighted average Runs Created (RC) gives the Dodgers bench 4.9 RC and the Padres 4.8 RC, a small win for Los Angeles. In addition, I would give the edge to Los Angeles for building depth at their most injury prone positions (Nomar at 1B and Luis Gonzalez at LF), while the Padres do not have strong backups for Khalil Green or Marcus Giles. It is certainly possible that injuries to starters could reverse the fortunes of these teams very quickly. Nevertheless, in th absence of injury, I have to say:

Edge: HUGE EDGE San Diego Padres (5+ wins)


Rotation
Taking the projections from my NL Rotation Analysis, the rotations compare as follow:

Los Angeles Dodgers: 4.54 EqERA, 948 IP
San Diego Padres: 4.36 EqERA, 980 IP

The Dodgers hype train this offseason seems to have been attached mostly to the "strong starting pitching" meme. The Dodgers certainly have a lot of depth (as is a trademark of the team since Ned Colletti took over). However, they don't appear to have a lot of quality. PECOTA does not think Jason Schmidt has the stuff to remain a staff ace, is hedging its bets on returning from injury Randy Wolf, and does not think much of Chad Billingsley (a viewpoint I share. Dude was mad lucky last year). Quietly, the Padres have put together a strong rotation with a true ace (Jake Peavy) and a number of quality innings eaters (Greg Maddux, David Wells, and Chris Young).

Edge: San Diego Padres (1-2 wins)


Bullpen
Taking the projections from my NL Bullpen Analysis, the bullpens compare as follow:

Los Angeles Dodgers: 3.97 EqERA
San Diego Padres: 3.90 EqERA

Two strong bullpens (by NL standards). PECOTA likes the front end of the San Diego bullpen better, but prefers the back end of LA's.

Edge: Push


Fielding
Taking the projections from my Team Fielding Preview, the defenses compare as follow:

Los Angeles Dodgers: -6 Runs/150 Games
San Diego Padres: +5 Runs/150 Games

As a final nail in the "Dodgers in 2007" coffin, consider that the San Diego team defense is projected to be quite strong while the Dodgers will be trotting out a bunch of guys that used to be good at defense.

Edge: San Diego (1+ win)


Putting it all Together
The Dodgers are getting a lot of misguided positive hype in my opinion, stemming largely from an incredible amount of "name-brand" depth. No doubt the Dodgers have household names at nearly every position, and young players with upside available for the inevitable injury. They have more quantity depth than almost any other MLB team. However, a huge quantity of mediocre is still mediocre. At season's end, I expect the Dodgers to be fighting for a 0.500 record. The Padres are projected to be superior in every aspect of the game, and the above analysis indicates that San Diego is 8-10 wins better than the Dodgers.

I'll keep the summation as short as possible:
San Diego is going to challenge for the NL West title, and Los Angeles is going to be one of the biggest disappointments in all of baseball.

VERSUS Part 2: Los Angeles Angels of Anaheim vs. Oakland Athletics

Editor's Note: Most of my baseball-related posts here at "Solvent is So Yesterday" have thus far focused on comparing teams across specific dimensions of baseball talent (e.g. hitting, fielding, and pitching). This method of presenting the data provides a lot of utility in explicating exactly what a team does well or not so well, but it also limits our ability to view teams at a holistic level. For example, the numbers indicate that the Red Sox will be strong on offense and in the rotation, but weak on defense and in relief. How good a team does that make them?

Like any good analyst, we need an alternate window into the data, different ways to mix and match the data. With that in mind, I think it is interesting to compare two teams across all the dimensions we have thus far studied, to get an idea of relative strength. The compared teams have been linked to each other, either by related characteristics or because they have a direct competition with each other.

In this, the second of a planned three part series, I compare the fortunes of the Los Angeles Angels of Anaheim and the Oakland Athletics, the key competitors for the AL West title.

Background
Since the collapse of the Seattle Mariners in 2004, the Angels and Athletics have been the class of the AL West, with each team finishing first or second every year. The Angels took the division title in 2004 and 2005, but faded last year, allowing Oakland to overtake them. My analysis indicates that both the Rangers and Mariners will be improved next year, but neither team figures to contend for the division title barring misfortune amongst the top 2.

Although the A's and Angels have played foe to each other on the field, the comparison between these two teams is just as interesting for their divergent team-building philosophies. The A's and their celebrity GM Billy Beane were famously profiled in Moneyball: The Art of Winning an Unfair Game, and are generally recognized as among the most numerical projection-reliant teams in MLB. The Angels represent the traditional scouting based approach to the game (cynics will correctly note that the supposed dichotomy here is largely media induced, and that the true team building philosophy -- building around cheap pre-free agent players -- of both teams is identical. But that's a point for another day).

Competitive Landscape
In order to reach the playoffs, what types of hurdles will these teams have to clear? The race for the AL playoffs is shaping up as an absolute dogfight. I count eight teams with legitimate claims on four playoff spots (in alphabetical order: Boston, Chicago, Cleveland, Detroit, Los Angeles, Minnesota, New York, Oakland). The numbers indicate that the Angels and A's may be a notch below the other six teams, but the difference is not overwhelming. More succinctly, the AL wildcard could certainly come out of the AL West. However, there will be up to five teams fighting for one wildcard spot, so the most likely path to the playoffs is a divisonal win.

Offense
Taking the projections from my AL Lineup Preview, the starting line-ups compare as follow:

Los Angeles Angels of Anaheim: 5.12 RPG
Oakland Athletics: 5.01 RPG

The Angels have a slight advantage on the offensive side of the ball (on the order of 2 wins per year), but neither of these offenses will scare many teams. By comparison, the offenses of their six main competitors are all expected to be substantially better (with the exception of the Chicago White Sox, and the ChiSox always seem to squeeze more runs out of their offense than I expect them to. See: Dye, Jermaine circa 2006, or Konerko, Paul circa 2005).

Comparing the benches, while recognizing that bench composition is still a relative unknown at this point:

Los Angeles Angels of Anaheim

Name	PECOTA (EqBA/EqOBP/EqSLG)
Jose Molina	.235/.284/.370
Shea Hillenbrand	.278/.323/.439
Maicer Izturis	.276/.355/.397
Kendry Morales	.260/.311/.436

Oakland Athletics

Name	PECOTA (EqBA/EqOBP/EqSLG)
Adam Melhuse	.219/.275/.376
Dan Johnson	.267/.364/.458
Marco Scutaro	.254/.325/.382
Shannon Stewart	.268/.330/.383

Both benches are average to slightly above average in comparison to the rest of the AL. A weighted average Runs Created (RC) gives the Angels bench 4.4 RC and the A's 4.3 RC, an almost negligible difference. However, I would give the Angels the bench advantage because they seem better suited to complement their starting lineup than the A's. Adam Melhuse is not really what you would hope for from a backup catcher -- he is neither proficient offensively nor defensively, and the only other potential backup catcher on the A's roster is Mike Piazza. Jose Molina can't hit either, but at least he is excellent defensively. Additionally, the quality of the Angels' three other bench players and the positional flexibility of the starting nine (specifically Chone Figgins and DH Juan Rivera) mean that almost any starting player save Vlad Guerrero can be rested without significantly impacting the offense. By contrast, the A's don't have quality backups (when considering defensive ability) for 3B, SS, 2B, or RF. Add it all up:

Edge: Los Angeles of Anaheim (2-3 wins)

Rotation
Taking the projections from my AL Rotation Analysis, the rotations compare as follow:

Los Angeles Angels of Anaheim: 4.06 EqERA, 994 IP
Oakland Athletics: 4.31 EqERA, 956 IP

The Angels have some of the best pitching in the AL (and indeed, all of MLB), with five above-average starters. However, Oakland comes out surprisingly well in this analysis as well, finishing with an above average rotation. Of course, the assumption implicit in these rankings is that the A's will get 34 starts out of Rich Harden, so....yeah.

Edge: Los Angeles of Anaheim (3 wins)


Bullpen
Taking the projections from my AL Bullpen Analysis, the bullpens compare as follow:

Los Angeles Angels of Anaheim: 3.56 EqERA
Oakland Athletics: 3.52 EqERA

Two very good bullpens, with a good closer and strong set-up men.

Edge: Push


Fielding
Taking the projections from my Team Fielding Preview, the defenses compare as follow:

Los Angeles Angels of Anaheim: +1 Runs/150 Games
Oakland Athletics: +21 Runs/150 Games

If there is one saving grace for the A's, it is that their team fielding is expected to once again be excellent. Regular readers of this blog know that I believe defense may currently be underrated by sabermetric fielding metrics. Note that this 20 run difference in fielding ability also assumes that Los Angeles will make the intelligent choice and put Juan Rivera in LF and use Garrett Anderson at DH. A full season of GA in left field might represent another 5 run advantage for the A's.

Edge: Oakland (2-3 wins)

Putting it all Together
The consensus view going into the season seems to be that the Angels are the favorites to take the division (TradeSports.com says a 50% chance of the Angels winning the division, and a 25% chance for the A's), and the numbers here don't refute that. Before giving my final predictions, I do think there are three points to consider that are currently difficult to incorporate numerically:

1. Injury risk - Will Carroll at Baseball Prospectus recently released his Player Health Reports (subscription required). Carroll gives both these teams a fairly high injury risk, especially the Oakland infield and the Anaheim outfield. As discussed in the offensive section above, I believe the Angels positional depth in the outfield is far superior to Oakland's infield depth. The loss of Chavez, Crosby, or Ellis (all of whom are viewed as moderate to serious injury risks) will significantly impact Oakland's chances of contending.
2. Defense - not to beat a dead horse, but Oakland's defense is going to be good, and this is an underrated component of team ability (in my opinion).
3. The Sabermetric Demerit - this is a name I came up with to describe the general underperformance that numerically oriented teams seem to experience when compared to preseason projections (if anyone has a better name, feel free to leave it in the comments section). The general concept is that in any competitive endeavor, anything that we don't properly value will be exploited by our competitors. Oakland, being a numerically based team, is likely using a set of analysis tools that are generally aligned with those I am using here (although they are no doubt more sophisticated). In contrast, the Angels use a player valuation methodology extremely different from that used here. As a result, the Angels are likely incorporating factors that we (and Oakland) are not, and there will be a systematic bias in our projections, such that we will always project the A's (and similarly Boston and Cleveland) to be better than they actually are, and we will always project the Angels (and similarly, the White Sox) to be worse than they actually are.

Summing up the points above, the strict numerical interpretation is that the Angels are ~3 wins better than Oakland. Defense works in the A's favor, but injury risk and the Sabermetric Demerit are on Anaheim's side. The resulting integration of all those factors indicates to me that the Angels are probably nearly five wins better than Oakland. Five wins is a large deficit to overcome, and as a result I would put Oakland's probability of winning the division as quite low (on the order of 20%). I am also going to make a prediction that I did not expect to make when I started this exercise, and say that I think the Angels have to be heavy favorites to win the division (i.e. 75% chance). There does not appear to be a team that will offer the Angels significant competition in 2007.

Update: 2/14/07
Happy Valentine's day! Soon after publishing this post, I headed over to one of my favorite blogs, Athletics Nation, and found that they had also posted a Angels vs. A's comparison. Although their conclusions were similar, I was also surprised to learn that Juan Rivera recently broke his league in Winter League ball, and will be out at least until midseason. In most cases, the loss of one player does not affect my projections very much, but the A's and Angels are in a sort of statistical "sweet spot" where a small change in talent can make a big change in playoff odds. Specifically, the loss of Rivera hurts the Angels in at least three ways:

1. Defensively. Garrett Anderson will now be the starting left fielder, a big downgrade from Rivera
2. DH inflexibility - I thought one of the Halos' big advantages this year was that they had a nice rotation of players available for 3B, LF, and CF, with players getting some rotating rest at DH. They have now lost some of that flexibility, although Chone Figgins can play a passable left field still.
3. Outfield depth. The Angels starting outfielders all got red lights from Will Carroll, meaning there is a good likelihood that Anaheim's outfield depth will become an issue this year. Previously, the Angels' fourth and fifth outfielders would have been Rivera and Figgins, both of whom are good enough to start in a pinch. Now the fifth outfielder will be...?? Maybe Angels fans know more about this than me - will Kotchman be asked to play some outfield? Does he have that ability?

Overall, I think the loss of Rivera is quite big, such that the five win advantage I had for the Angels before, might be closer to 3 wins now (maybe 3.5). The playoff odds now go from 80% Angels/20% A's, to more like 70/30, a big change.

VERSUS Part 1: Milwaukee Brewers vs. Arizona Diamondbacks

Most of my baseball-related posts here at "Solvent is So Yesterday" have thus far focused on comparing teams across specific dimensions of baseball talent (e.g. hitting, fielding, and pitching). This method of presenting the data provides a lot of utility in explicating exactly what a team does well or not so well, but it also limits our ability to view teams at a holistic level. For example, the numbers indicate that the Red Sox will be strong on offense and in the rotation, but weak on defense and in relief. How good a team does that make them?

Like any good analyst, we need to provide alternate windows into the data, different ways to mix and match the data. With that in mind, I think it is interesting to compare two teams across all the dimensions we have thus far studied, to get an idea of relative strength. The compared teams have been linked to each other, either by related characteristics or because they have a direct competition with each other.

In this, the first of a planned three part series, I compare the probable fortunes of the Arizona Diamondbacks and Milwaukee Brewers, two teams that have received offseason hype as potential breakout candidates.

Background
Two weeks ago, Ken Rosenthal of FoxSports.com published an article entitled Four Teams that Could Surprise in '07, in which he named both the Diamondbacks and Brewers as potential sleepers for the upcoming season. Although Rosenthal also listed the Rockies and Orioles in his article, his reader poll indicates that the wisdom of the crowd is aligned toward the D-backs and Brew Crew (actually, Rosenthal's readers see the Brewers as the runaway favorites to surprise--is it possible to be an expected surprise?--garnering 50% of the vote to the Diamondbacks 25%). These teams are linked by more than a Rosenthal article, however, as both teams are at similar points in their success cycle--incorporating a lot of young talent at the major league level, and thus providing an expectation of significant upside. Additionally, Arizona and Milwaukee have been involved in two fairly large-scale trades in the past few years. The first was the Brewer's absolute steal of a trade, in which they obtained Junior Spivey, Craig Counsell, Lyle Overbay, Chad Moeller, Chris Capuano, and Jorge de la Rosa from the Diamondbacks for Richie Sexson and Shane Nance. And just this year, the Diamondbacks sent catcher Johnny Estrada and pitcher Claudio Vargas to the Brewers in exchange for pitchers Doug Davis and Dana Eveland.

Competitive Landscape
In order to reach the playoffs, what types of hurdles will these teams have to clear? Well, from the outset, let's say this: these teams are contenders for the postseason because they play in the NL. Put either team in the competitive AL and we probably wouldn't be having any discussion of breakout possibilities. Beyond that, both teams play in divisions in which there is (to me, anyways) one clearly superior team. The Brewers match up against the Cardinals in the NL Central, and the San Diego Padres play foe to the Diamondbacks in the NL West (astute readers might be wondering what happened to the Astros, Cubs, Dodgers, and Giants in these discussions. I expect, for various reasons, that these teams will not really be the contenders that people are expecting, but that is a conversation for another post). Thus, Arizona and Milwaukee's path to the playoff would likely go through the Wild Card spot, and as such, they are in direct competition with each other.

Offense
Taking the projections from my NL Lineup Preview, the starting line-ups compare as follow:

Arizona Diamondbacks: 4.82 RPG
Milwaukee Brewers: 4.77 RPG

These teams are as close as possible on the offensive side of the ball, as their starting lineups are projected to differ by less than 10 runs over the course of an entire season. Both teams lack a truly elite hitter at any position, but generally receive average production from almost every lineup spot. PECOTA likes a lot of the young players on both teams (especially Chris Young and Prince Fielder), and expects both teams to have generally solid offensive performance.

Comparing the benches, while recognizing that bench composition is still a relative unknown at this point:

Milwaukee Brewers

Name	PECOTA (BA/OBP/SLG)
Damian Miller	.253/.323/.393
Tony Graffanino	.275/.341/.407
Craig Counsell	.258/.335/.353
Gabe Gross	.262/.353/.445
Brady Clark	.270/.342/.384

Arizona Diamondbacks

Name	PECOTA (BA/OBP/SLG)
Miguel Montero	.259/.324/.439
Tony Clark	.246/.316/.459
Alberto Callaspo	.283/.336/.398
Scott Hairston	.265/.333/.477
Jeff DaVanon	.270/.365/.409

The bench edge goes to the Diamondbacks, who have more power at every position than the Brewers. A weighted average Runs Created (RC) for Milwaukee's bench comes in at 4.5 RPG, versus 4.8 RPG for Arizona's bench. It's not a big advantage, but an advantage nevertheless.

Edge: Arizona (slightly)

Rotation
Taking the projections from my NL Rotation Analysis, the rotations compare as follow:

Arizona Diamondbacks: 4.29 EqERA, 977 IP
Milwaukee Brewers: 4.40 EqERA, 990 IP

PECOTA likes Milwuakee's Ace over Arizona's (Ben Sheets versus Brandon Webb) but Arizona's Top 2 over Milwaukee's (Randy Johnson versus David Bush/Chris Capuano). In my rotation analysis, I ranked Arizona and Milwaukee as the NL's best rotations for their combination of good EqERA's with strong projected innings pitched totals. Both teams have good depth as well, with sixth and seventh starters clearly above replacement level. The starting rotation will be a strength for both teams and is indeed the main driving force behind their expected break-outs, but once again, we have to say:

Edge: Arizona (slightly)

Bullpen
Taking the projections from my NL Bullpen Analysis, the bullpens compare as follow:

Arizona Diamondbacks: 4.01 EqERA
Milwaukee Brewers: 4.04 EqERA

Both bullpens grade out as above average by NL standards. Milwaukee has the best pitcher (Francisco Cordero) out of the group, while PECOTA likes Arizona's front three of Jorge Julio, Jose Valverde, and Brandon Medders. The open question is: how good is Derrick Turnbow? Is he 2005 good, or 2006 good? If it's the former, the Brewer's bullpen is clearly superior. As it is, however, PECOTA is hedging it's bets.

Edge: Push

Fielding
Up until this point, the picture we have painted is of two extremely evenly matched teams, both teams having the same strengths and weaknesses. But you had to know something interesting was coming, right? I've saved the best for last, the issue of team fielding. Taking the projections from my Team Fielding Preview, the defenses compare as follow:

Arizona Diamondbacks: +13 Runs/150 Games
Milwaukee Brewers: -10 Runs/150 Games

Here, we see the elephant in the room--the Diamondbacks defense is going to be quite strong, while the Brewers are going to be well below average. Additionally, this divergence is a direct result of the teams' young talent. Where the Diamondbacks rookies are projected as quite strong defensively, the Brewers core of Prince Fielder, Rickie Weeks, and Bill Hall (switching from SS to CF) is fairly weak. The difference of 23 runs over 150 games (or 25 runs per 162 games), is worth 2.5 wins on its own. I am also of the belief that defense might be more important than our measurement systems give it credit for -- the last two MLB breakout teams (Chicago White Sox in 2005, and Detroit Tigers in 2006) got there largely based on tremendous defensive seasons.

Edge: BIG EDGE Arizona

Putting it all Together
Both the Brewers and Diamondbacks are trying to build championship caliber clubs from a young core, and each will be relying on strong starting pitching to drive their 2007 results. But the Diamondbacks have a big additional advantage: a strong team defense that the Brewers can only dream of. Neither team will overwhelm opponents with an offensive display, and thus need to contribute in other ways. In short, the Diamondbacks will have those contributions, and the Brewers won't.

Both the Brewers and Diamondbacks have the superficial look of a breakout candidate, but as the season winds down I expect the Diamondbacks to be in the thick of the wildcard race, with the Brewers hoping for another late-season St. Louis collapse.

Why does the AL dominate the NL?

Which league is better, and why are they better? This is a question that seems to have been discussed ad infinitum the past year or so, prompted mostly by the AL's uber-pwnage of the NL in interleague games the last two years. The first part of my question, "which league is better?", is not particularly hotly debated. The AL is clearly better, as evidenced by their 262-241 record versus the NL in 2005-2006. Indeed, the AL's Runs Scored and Runs Allowed in interleague play the past few years imply a winning percentage of 53-54% versus the NL. The bigger question is "why is the AL so much better?". Is it the pitching, the hitting, or a combination of both? In my previous posts on team-level projections, you may recall that I found the offensive level in the NL to be comparable or even superior to the AL, but that the AL held a large advantage both in starting pitching and relieving.

To quantify those findings a bit further: to compare AL and NL offenses, I take my NL projections and add 0.5 runs per game (RPG) (because we will be replacing the pitcher's 0.200/0.200/0.200 line with some sort of average hitter). In doing so, I find the average AL starting lineup is projected to score 5.24 RPG, with the corresponding NL average of 5.34 RPG (before my dear readers send me emails informing me that these league averages are all-together too high, please remember that these estimates assume that the starting eight or nine play every inning of every game). Additionally, I found that the quality of projected NL benches was slightly superior to AL benches. By contrast, AL and NL rotations came in at 4.40 and 4.58 RPG, respectively, with the bullpen difference being even larger (3.77 to 4.13). Could the AL's dominance truly be a function of the pitching only?

To answer that, I first decided to take a quick trip in the time machine to the beginning of 2006. After all, 2007 hasn't happened yet, so my projections for the upcoming season are not particularly informative to what has already happened. What I find is that in preseason 2006, my predictions of league offensive strength were exactly reversed, 5.33 RPG for the AL, and 5.23 RPG for the NL. So, using the exact same projection system, it looks like the NL has gained offensive strength this offseason, at the expense of the AL. In contrast, the bullpen projections were 4.05 and 4.21 RPG for the AL and NL, a much smaller gap than this year (note: I did not do preseason projections of rotation strength last year, and the defensive projections both years give the AL a slight 0.03 RPG edge). So, the take-home message is that as of preseason 2006, I expected the AL to have a small positive advantage both on the offensive and pitching side of the ball.

Can we achieve and independent confirmation of these results, using the actual 2006 seasonal data? Well, at this point I should mention that there has been a lot of very good work already done on this topic, using more advanced statistical methods than I will use here. For example, Mitchel Lichtman did a three part study in July 2006, the conclusion of which was that the AL's advantage was actually all on the hitting side. My comments about this work are that they certainly do not mesh with what I have seen here, and that while I believe his statistical methods were rigorous, his interpretation of the data required certain assumptions that may not be valid. See this blog conversation for more. In January of this year, John Walsh wrote an article on The Hardball Times website in which he found that hitters switching from the AL to the NL experienced a 0.029 OPS boost, which one can attribute to the lower quality of pitching in the NL. The magnitude of this effect was estimated at 50-60 runs, which is about 60% of the effect needed to explain the AL's advantage. In this analysis, then, it's the AL pitching, not the hitting that dominates.

I am going to propose an extremely simple test, that I think will lead to an interesting prediction at the end. To truly determine where the league dominance lies and why, we need at least two metrics. One metric tells us which league is better. We can use interleague records, and the message here is that the AL is superior. A second metric is needed to determine whether the hitting or pitching contributes more to this dominance, and I propose here that a simple metric is the runs per game (RPG) difference between the AL and NL for a given year. Over the past 13 years, the AL RPG scoring rate has been ~0.35 RPG higher than the NL, on average. This is due, of course, to the presence of the DH in the AL. However, the differential has been as high as 0.71 RPG in 1996, and as low as 0.16 RPG in 2001. When the differential is below average, we can infer that this means that either the AL pitchers are winning the war, or the NL hitters. Think about it - for the RPG differential to fall, something is either causing the RPG to drop in the AL (i.e. pitching) or the RPG to rise in the NL (i.e. the hitting). Conversely, an above-average RPG differential means the reverse (NL pitching dominance, or AL hitting dominance). Combining the two metrics, then, tells us who is dominating and why. This is summarized in the table below:

	RPG differential below average	RPG differential above average
AL wins interleague	AL pitching dominates	AL hitting dominates
NL wins interleague	NL hitting dominates	NL pitching dominates

Still with me? Okay. The observed RPG differential in 2006 was........0.21 RPG, which is quite close to the minimum differential ever achieved. To me, this lends credence to the theory that AL pitching is currently dominant.

What can our PECOTA projections tell us then about what to expect for 2007's RPG differential? Well, we already know that the offensive RPG estimates have moved 0.2 runs to favor a higher RPG environment in the NL (that is, the NL should score 0.2 RPG more next year than last year, relative to the AL). Additionally, the bullpen projections have moved to favor a lower run environment in the AL relative to the NL. Both of these metrics are moving in the same direction, favoring a lower RPG environment in the AL relative to the NL. Put those together, and it is not unrealistic to imagine that the 0.21 RPG differential between the AL and the NL could disappear completely, creating a unique condition in which the NL outscores the AL. At the very least, I expect the RPG differential to break through its previous low of 0.16 RPG. For my two readers, I encourage you to bookmark this post, so that I can be summarily taunted when this prediction turns out to be wrong.