Lou is apparently considering swapping Hill and Marquis in the rotation this time around so that Hill would face Philly on Friday and Marquis would face Pittsburgh tonight. ¿Qué? Without even looking at the numbers, let me make the following observations:

1) Hill is a flyball pitcher, and Philly’s ridiculous lineup/ballpark don’t suit his style. Marquis, on the other hand, is a groundball pitcher, and will probably be equally bad in either ballpark.

2) Why mess with the rotation at this point in the season?

OK, now the numbers: Marquis, somewhat predictably, has not been very good in his career against the Phillies’ starters, with the important exception of Jimmy Rollins, whom he OWNS. The current Phillies roster’s cumulative career numbers against Marquis are .285/.372/.397. The bright spot? He’s only given up two homers to the group in 151 ABs, one to Jayson Werth and one to Pat Burrell. What about the Pirates? Well, a couple of early-season starts last year excepted, they’ve hit him hard. Bay, McLouth, and Doumit in particular have had great success against Marquis. The roster’s cumulative line is .259/.325/.524, and they’ve hit nine homers in 147 ABs. To summarize: the current Pirates roster is just as good against Marquis as the current Phillies roster, and probably a bit better.

As for Hill, he’s done well against the Pirates in his short career: the current roster has posted an anemic .218/.287/.308 line against him in 89 PAs. What about Philly? As you may have guessed, they’ve pounded him to the tune of a collective .230/.319/.590 line, including six homers in just 61 ABs.

I can’t really figure out what Lou is thinking: this is a situation where common sense tells you not to switch them (Hill=flyball=not good at Philly, etc.) and where the stats confirm that call. He must be thinking something along the lines of this: “Hill is a better pitcher, so why waste him against a crappy team; let’s put him against the better team and put Marquis against a team that’s not as potent offensively.” But that thinking is flawed: a team’s offensive potency is an average over the collection of pitching it faces, just as a pitcher’s numbers are an average over the hitters he faces. Generally speaking, you want a better pitcher facing a better team, but in this case, Marquis is a better pitcher against the Phillies given their ballpark configuration, etc., while Hill is the better pitcher against the Pirates. Can someone from the NBA come in and explain matchups to Lou?