Dissecting the Kyle Lohse Start: Beware! FIP! by Bradley Woodrum April 5, 2012 Opening Day 1.5 featured a one-game series with the defending world champs, the St. Louis Cardinals, and the league’s latest makeover recipient, the Miami Marlins. Righty Kyle Lohse earned the Opening Day honors for the Cardinals on the merit of being not recently or presently injured, and much to the surprise of many, Lohse took a perfect game no hitter into the 7th inning. His line from the game: 7.1 IP, 1 ER, 3 K, 0 BB, 8 GB, 10 FB, 2 LD All told, that comes to a 1.23 ERA, 1.49 FIP, 2.94 xFIP, and… a 4.22 SIERA… Everything but that SIERA number suggests Lohse had a great start. Let’s find out why. The most important item to remember — and not just with Lohse, but with Josh Johnson, Felix Hernandez, and every pitcher who has pitched in this extra-young season so far — is that the FIP constant here at FanGraphs is not, well, constant. The Dark Overlord has some magical algorithm in place to keep the constant (usually around 3.2) variable according to the league’s run environment. Because the regular season has all of three games of data right now, that constant is unusually low — in the ones last I heard. So Lohse’s 1.49 FIP is actually less impressive in the context of the four team “league.” His FIP- is 109 and his xFIP- is an even more troubling 164. With a 3.2 constant, the comes out to a 2.79 FIP and a 4.56 xFIP. Suddenly his SIERA, which sits near his career levels, does not look nearly as strange. Which is all to say: Beware of FIP right now! Just because a number looks intrinsically good, it’s best to reference FIP- or SIERA to ensure the number is not biased by the current run environment. So what was it about Lohse’s start troubled SIERA? Lohse did not walk anybody — though he did hit Emilio Bonifacio in the 4th inning (before removing him with a double play) — and his strikeout rate (about 12%) was not bad. Presumably, it must be his balls in play. Lohse allowed 20 balls in play, but only 2 hits — good for a .100 BABIP. Last year, grounders went for a .237 BABIP, flies a .137 BABIP, and liners a .714 BABIP. If we apply these percentages to Lohse’s numbers, he comes out with about 2 ground ball hits, 1 fly ball hit, and 1 line drive hit (an expected BABIP of .200). SIERA is sensitive to what kinds of hits Lohse allows, but four predicted hits is not terrible — in fact, the 66% ground ball rate is much better than his career numbers. However, his career homerun per flyball rate — 9.7% HR/FB — suggests he would have typically allowed at least one homer in a game such as this — which makes sense. A guy averaging 1.10 HR/9 probably would allow a homer in the typical game where he pitches nearly into the 9th inning. In fact, he almost did, too. In the bottom of the second inning, Giancarlo Stanton redirected a pitch to deep center field, going for about a 405-foot out. The new Marlins Park should play like SafeCo Field with even fewer HRs to center field, which could be bad news for Stanton, who, more than one time, took advantage of Dolphin Stadiums’ cut out in CF: Stanton’s Dolphin Stadium Homers Courtesy of Katron.org. All this to say: (1) Lohse pitched well, but still looks very much like his Lohsian self, and (2) the new Marlins Park seemed to help him out a bit, but that may mean more for Miami’s home run hitters than for Lohse, and (3) above all, look at FIP- and xFIP- and all the minus stats instead of their traditional counterparts — especially early in the season. None of these stats may not be very predictive right now, but at least the minus stats (and SIERA) are better at being descriptive.