Stats vs. Gut -- The Ribbie Reporter replies

As you'll see from our earlier post, the Nachoman and I are beginning a conversation on stats vs. gut feelings. I got the idea from this after Kansas City Manager Trey Hillman let home run prone Kyle Farnsworth face Jim Thome, even though Thome hits lots of home runs and has always had his way with righties like Farnsworth. In contrast, Thome is quite pedestrian against lefty pitchers. I agree with the Nachoman that it's not that useful to rely on limited sample sizes -- looking at how one pitcher as done against a batter during the last few years, for example. Twenty at bats simply don't give us enough information. That's a favorite strategy of Tony LaRussa; he likes to know how each of his batters has done against every pitcher on the opposing team, and vice versa. I don't think that's very useful.
I do strongly believe, however, in looking at platoon splits. That brings us back to Mr. Thome. In his career, Thome has hit .296/.431/.620 (AVG/OBP/SLUG) against RHP – against lefties, he has hit .240/.342/.442. Can you tell the difference? In that case, stats clearly show that it's a much better decision to send in a lefty to face Mr. Thome. It was the bottom of the 8th, Royals up one. Thome was hitting with two outs and two on. If you get him out, you have a good chance to win the game. If he gets a hit, you start fresh (if he gets a homer, as he did, you lose the game).
Yes, it's important to consider how hot or cold a pitcher is. Hillman decided in this case that Farnsworth was "hot" because he was "throwing strikes." Unfortunately, he was also throwing hittable strikes. And again, even if a lefty is cold, his strikes -- across Thome's long career -- have given the slugger more trouble than a lefty's strikes. See what I'm saying?
Finally, I want to address the Nachoman's "Dandelion effect." He argues that a defense will be sluggish after having to stand around and wait for the pitching change. I think that's nonsense. Sure, defensive lapses may happen on occasion after a pitching change. However, they also happen during the normal flow of the game, and I don't think they're more common after mid-inning pitching changes. Major League players are paid millions to pay attention and field their positions. Most of them know that if they stop fielding somebody else will get their spot (that is, unless the awful fielder can hit .300 and have 30+ homers a year... then all defensive lapses are excused).
Stats can teach manager a lot -- it can even teach them to take it easy and not try to do too much. If Hillman wants to completely ignore stats and manage with his gut, I can't stop him. But I am convinced he'll be hurting his team in the long-run.

Ribbie Reporter -- You be the manager

Opening Day, Take II. Today is going to be a participatory blog post, where you get to pretend to be a real live manager (in this case Royals manager Trey Hillman).

Let's set the scene, shall we? Bottom of the 8th, Royals leading 2-1 in Chicago over the White Sox. Ace Gil Meche has turned in a fine start, but is tiring and is still working up to mid-season endurance. So you, dear manager, turn to new reliever Kyle Farnsworth, even though he gives up homers at an alarming rate (15 in 60 innings last year, a rate of 2.3 per 9 innings). The Sox get a bunt single. Then there's a flyout. Then a hit and run single, followed by another fly out. So there are first and third, two outs, your team up by one, Jim Thome coming to the plate.

Now, let's review a few pertinent stats: Mr. Thome has hit 542 home runs in his career, 42 of them against KC (by far the most he's hit against any team). Mr. Thome is a lefty, and he has a career OPS (on-base % + slugging %) of 1.052 against righties like Farnsworth. Against lefties it's a much more modest .788 (THIS IS A HUGE DIFFERENCE). Farnsworth's career numbers also show that he's much better against righties than lefties.

Now here's where we participate. As manager, you have a few options:
A) Bring in lefty Ron Mahay to face Thome. Mahay is not much better against lefties than righties, but remember Thome drops off significantly against lefties. Mahay also gives up far fewer homers than Farnsworth.
B) Bring in righty closer Joakim Soria, who held lefties to a .167!!! batting average last year. He's your best reliever, and getting the out here goes a long way to sealing the game. Also, a four out save won't make his arm fall off, and he should be fresh since it's opening day.
C) Leave in Farnsworth and take your chances.

Which would you choose? A, B or C? And which do you think the real manager chose?