his numbers would be much better away from PETCO, he’s actually a very good defender and his contract is ridiculously team-friendly.

a .732 OPS from a guy who plays half his games in Petco isn’t terrible, certainly not from a platoon SS. It’s below the park-adjusted average for a 1B, but not by all that much. NL 1Bs are hitting .811 on average. Petco deflates both HRs and Doubles more than any other park in the league. Figure every player has at least some platoon split, and Gonzalez’s split v. lefties really isn’t much of a big deal at all.

with comparing a starting 1B with a replacement platoon player who can mash lefties is that that player takes up a bench spot. Team’s can’t platoon every player with an accentuated weakness against same-handed pitching. San Diego could easily find someone who’s a good bet to put up slightly better numbers against lefties, but the extra couple of runs they’d get out of that isn’t worth a roster spot that could be used for better purposes than another player with limited defensive versatility (which applies to most of the AAAA lefty-mashers floating around on the free pile).

Adrian Gonzalez got 261 PA’s against lefties last year. Using wOBA, the difference between Gonzalez and a guy who can OPS ~.800 against lefties is about 8 runs, and that figure is misleading, because Gonzalez gets a disproportionate number of at-bats against lefties, since he’s a guy a manager will bring in a LOOGY to face in order to play the percentages. If the team were to bring in a bona-fide lefty masher capable of a .900 OPS, he’d be worth 10 runs more than Adrian Gonzalez with the bat, minus whatever you lose by an opposing manager’s decision to make him face a righty reliever late in the game (probably at least 2-3 runs given the high leverage situations where righty specialists would be brought in), and minus whatever you’d be giving up on defense - Gonzalez isn’t a gold glover, but it’s not really common to find a lefty-mashing platoon 1B who can bring much at all to the table. Call that 2 runs.

Add it up, and the difference between Gonzalez v. lefties and a guy who could put up a .900 OPS against them is worth about half a win. His platoon split’s not a big deal. His 3.5 WAR/year at his low salary, on the other hand, would be very difficult to replace.

And 2007-2009 he’s OPSed right around what Morneau, Carlos Pena, Carlos Delgado, and Prince Fielder have, and no one would be saying any of those guys should be benched in a tight spot. He’s a pretty standard lefty slugging first baseman. Lefty sluggers like Papi and Howard are the exception, not the rule, as most power hitting lefties are going to have some trouble against lefthanders.

Can you name five first baseman that you’d rather have than Gonzalez? Factoring in defense, his numbers away from Petco, and his contract. Because it’s pretty tough.

Who are these bums on the street you’d replace him with who could replicate his numbers out of the first base spot?

If the only conclusion that can be taken from the data is that the data itself is inconclusive, we need a better system of evaluation.

That being said, I’m aware of the differing opinions on his glove. James Loney he is not, but I think even his detractors would suggest that he’s at least average and obviously his supporters think he’s quite outstanding.