We haven't done this in a while. If you haven't been paying close attention to the numbers, you may be surprised by some of these comparisons:
Player A: .265/.342/.496, 28 HR, 72 RBI, 132 OPS+
Player B: .283/.352/.468, 22 HR, 64 RBI, 134 OPS+
Player A: .271/.359/.448, 22 HR, 117 OPS+, 1.0 WAR
Player B: .260/.370/.446, 17 HR, 131 OPS+, 3.1 WAR
Player A is Prince Fielder, Player B is Carlos Santana. Of course, I left out RBIs, and Fielder has 95 of those compared to 60 for Santana (Fielder has 81 more plate appearances). Has Fielder had a great RBI season? According to Baseball-Reference, the average major leaguer drives in 65 runs in 622 plate appearances, so Fielder is +30. Sounds good. But ... he's also had 98 more runners on base than the average hitter. In WAR, Santana moves ahead thanks to Fielder's poor defense and a positional adjustment for Santana, because he's played a lot behind the plate.
Player A: .233/.291/.448, 29 HR, 84 RBI, 1.5 WAR
Player B: .238/.299/.422, 19 HR, 62 RBI, 1.0 WAR
Player A is Mark Trumbo and Player B is Angels teammate Josh Hamilton. Trumbo has escaped criticism because he has more home runs and RBIs, but he's also another sub-.300 OBP guy in the middle of the Angels' lineup.
Player A: .243/.311/.433, 17 HR, 102 OPS+
Player B: .267/.316/.420, 18 HR, 98 OPS+
Looks pretty close, right? What if I told you one of these guys has 101 RBIs and has been touted as an MVP candidate by some (OK, at least one prominent national broadcaster), and the other guy has 60 RBIs.
Player A is Twins second baseman Brian Dozier and Player B is Reds second baseman Brandon Phillips. In terms of WAR, Dozier has the bigger advantage, 3.8 to 1.7. Look, Phillips is hitting .354 with runners in scoring position. He's also hitting .211 with a .249 OBP with the bases empty; those at-bats count, too. Phillips has made the fourth-most outs in the NL.
Player A: 209 IP, 145 H, 47 BB, 201 SO, 6.6 WAR
Player B: 187.2 IP, 158 H, 40 BB, 199 SO, 6.2 WAR
Pretty similar. Both are left-handed. One stat I left out: Player A has a 1.89 ERA, while Player B's is 2.97. Player A, of course, is Clayton Kershaw while Player B is Chris Sale. How can Sale be close despite an ERA a run higher? A few things. We're talking an NL pitcher versus an AL one, so Kershaw's run-scoring environment is a little lower. Home park: Kershaw pitches in Dodger Stadium, a good park for pitchers, while Sale pitches at The Cell, a hitter's park. Quality of opponents: Kershaw's opponents have averaged 4.20 runs per game compared to 4.51 for Sale's. Defense: Kershaw's is good, Sale's isn't. So why has nobody noticed Sale's season? He's 10-12. Put him on the Tigers and he'd be competing with Max Scherzer for Cy Young Award honors.
Player A: 193 IP, 180 H, 43 BB, 174 SO, 3.50 ERA, 4.1 WAR
Player B: 184 IP, 169 H, 50 BB, 172 SO, 2.98 ERA, 4.0 WAR
Cole Hamels is A, and Mat Latos is B. Of course, Hamels is 6-13 and Latos is 14-5, obscuring the fact that Hamels has been outstanding. Hamels was 1-9 with an ERA approaching 5 through May, and those bad starts (or good starts) stick in our memories. But since July, he's made 12 starts and posted a 2.17 ERA, allowing more than two runs just twice (though he has just four wins). He's still one of the best left-handers in the league.
Player A: 5-2, 1.48 ERA, 38 saves, 2 blown saves
Player B: 4-2, 2.19 ERA, 41 saves, 6 blown saves