Turn on “Baseball Tonight” these days and you’re sure to see one of the insightful commentators mention just how loaded the National League is this season. The senior circuit, indeed, has had its share of dominating performances. The top seven players in Value Over Replacement Player are all National Leaguers (yes, Dorothy, the list does include Mark Loretta). Although Johan Santana has surged to the top of the pitching VORP board, 11 of the top 16 performances on that list belong to NLers.

Dominating individual performances, however, do not reflect a dominant league. On the contrary, dominating performances are easier to come by when the league talent pool is thinner; think of the gaudy numbers that NCAA players or preps put up. As baseball’s talent base has grown deeper, the number of dominant performances has decreased, with the standard deviation of most critical statistics decreasing over time (see also: Stephen Jay Gould’s essay on the disappearance of the .400 hitter). That ALers are having a tougher time tearing their league a new one suggests that it is the better league, and not the worse one.

Can we conjure up some further evidence in support of this contention? Let’s take a look at the performances of players who have switched leagues in the past year; hitters who accumulated at least 200 plate appearances in the National League last season and at least 200 PA in the AL thus far this year, as measured by Equivalent Average. By my count, there are 24 such players. By the way, any resemblance to the Davenport Translations is purely intentional–Clay uses a very similar, if more exacting, process to come up with his numbers.

Table 1: NL to AL Crossovers – Hitters

Player              Team    2004 EqA   2003 EqA

Vladimir Guerrero    ANA     .328       .326
Jose Guillen         ANA     .305       .325
Javy Lopez           BAL     .297       .334
Mark Bellhorn        BOS     .288       .232
Jose Uribe           CWS     .264       .232
Timo Perez           CWS     .215       .237
Ron Belliard         CLE     .283       .250
Ivan Rodriguez       DET     .309       .291
Rondell White        DET     .286       .273
Matt Stairs          KCR     .266       .312
Gary Sheffield       NYY     .326       .337
Miguel Cairo         NYY     .254       .236
Kenny Lofton         NYY     .268       .278
Mark Kotsay          OAK     .279       .262
Damian Miller        OAK     .273       .239
Jolbert Cabrera      SEA     .259       .269
Rich Aurilia*        SEA     .231       .260
Tino Martinez        TBD     .288       .273
Jose Cruz, Jr.       TBD     .275       .272
Geoff Blum           TBD     .223       .229
Robert Fick          TBD     .209       .263
Eric Young           TEX     .274       .254
Gary Matthews, Jr.   TEX     .266       .264
Rod Barajas          TEX     .236       .198

Average                      .271       .269

* Aurilia's 2003 stats include his 2004 performance since returning to the NL.

There is not much evidence that the AL is the superior league. In fact, the hitters have their EqA by a trivial amount on average. While players like Rich Aurilia and Robert Fick have struggled in new surroundings, others like Mark Bellhorn and Juan Uribe have thrived.

How about the opposite side of the coin?

Table 2: AL to NL Crossovers – Hitters

Player              Team    2004 EqA   2003 EqA

Todd Walker          CHC     .274       .263
D'Angelo Jimenez     CIN     .261       .261
Carlos Beltran**     HOU     .324       .298
Milton Bradley       LAD     .279       .322
Ben Grieve           MIL     .269       .267
Tony Batista         MON     .231       .230
Mike Cameron         NYM     .284       .279
Shane Spencer        NYM     .264       .253
Todd Zeile           NYM     .239       .235
Karim Garcia*        NYM     .230       .237
Marlon Anderson      STL     .221       .260
Ramon Hernandez      SDP     .283       .274
Terrence Long        SDP     .271       .239
A.J. Pierzynski      SFG     .265       .285
Dustan Mohr          SFG     .300       .250
Deivi Cruz           SFG     .267       .224

Average                      .266       .261

* Garcia's 2003 stats include his 2004 performance since returning to the NL.
** Beltran's statistics represent his 2004 performances in the NL and AL, respectively.

We’ve thrown Carlos Beltran into the mix, as he has already accumulated 200 PAs in both leagues this season, to go along with a whole boatload of other impressive numbers. As a group, the AL to NL crossovers have improved their performance; to borrow from market-geek terminology, there are twelve advancers against just four decliners, with the average player improving by about five points of EqA.

We can evaluate the performances of pitcher crossovers, too. We will use Normalized Run Average (NRA), one of the many statistics that are updated daily on our revamped and highly underrated DT player cards, as our basis for comparison. Pitchers must have thrown at least 50 innings in each league in order to qualify.

Table 3: NL to AL Crossovers – Pitchers

Player              Team    2004 NRA   2003 NRA

Curt Schilling       BOS     3.08       3.12
Carlos Silva         MIN     4.51       6.45
Joe Nathan           MIN     1.35       2.38
Javier Vazquez       NYY     4.33       3.61
Kevin Brown          NYY     4.24       3.24
Paul Quantrill       NYY     4.45       2.61
Mark Redman          OAK     4.51       3.97
Ron Villone          SEA     5.54       4.20
Miguel Batista       TOR     4.22       3.94
Justin Speier        TOR     3.03       4.47

Average                      3.93       3.80

Once again, we are limited by a small sample size and a wide degree of variance in the individual performances, but pitchers crossing over to the AL have suffered a small performance decline, with their NRA increasing by an average of 13 points. (Admission: every year there are a few outstanding performances that I manage to overlook in the heavy traffic of the baseball season, sometimes until it’s time to run the new round of PECOTA forecasts in the winter. Has Joe Nathan been awesome this year or what?).

By contrast, the AL to NL pitching crossovers have done well as a group:

Table 4: AL to NL Crossovers – Pitchers

Player              Team    2004 NRA   2003 NRA

Steve Sparks         ARI     7.04       7.02
Casey Fossum         ARI     5.86       5.07
LaTroy Hawkins       CHC     2.56       1.90
Cory Lidle           PHI     5.70       5.02
Roger Clemens        HOU     3.39       3.94
Andy Pettitte        HOU     3.74       4.11
Jeff Weaver          LAD     4.02       6.51
Doug Davis           MIL     3.82       4.18
David Wells          SDP     4.12       4.33
Jeff Suppan          STL     4.48       5.35

Average                      4.47       4.74

Here too, the force of our conclusion is limited by the small sample size, but we’re beginning to put a case together that the AL is, in fact, the stronger league. All told, 18 of 26 former AL players have improved their performance upon converting leagues, while the NL expatriates are split just about evenly between advances and declines.

It turns out, though, that there is some much stronger evidence for the AL’s superiority that is staring us right in the face. Go back and read the list of crossovers presented in the previous tables.

Got it? As it happens, regardless of how well the players have managed to perform in their new leagues, the quality of NL-to-AL crossovers is much higher than the other way around. Eight players who posted VORPs of 40 or higher in the National League last season–Ivan Rodriguez, Gary Sheffield, Vladimir Guerrero, Jose Guillen, Javy Lopez, Kevin Brown, Javier Vazquez and Curt Schilling–are playing in the AL this year. Just three AL players with VORPs of 40 or higher have moved leagues, and that includes Beltran, who has only had a couple of months in his new digs.

Here are the cumulative 2003 VORPs for all the crossovers listed above:

Table 5: Crossovers – 2003 VORP summary

NL to AL Hitters         570.2
NL to AL Pitchers        332.2
Total                    902.4

AL to NL Hitters         303.3
AL to NL Pitchers        119.0
Total                    422.3

Difference               480.1

It would be hard to overstate the enormity of that difference. The National League has had the short end of the stick in terms of player movement, suffering a net loss of about 480 points of VORP, a figure equivalent to nearly 50 wins. To put it somewhat differently, the average NL team has lost about three or four wins’ worth of talent in the last year alone, while the average AL team has gained about the same amount.

That is not to suggest that Albert Pujols, Adrian Beltre, Jason Schmidt and so forth are having anything but outstanding seasons; they are great players one and all. But if they were playing in the AL this season, they might be finding the going at least a little bit tougher.

Thank you for reading

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