From April 3, 2013 to June 3, 2013, Lance Lynn started 12 games for the St. Louis Cardinals. In those 12 games, he went 8-1 with a 2.76 ERA. He threw 75 innings, just over 6 innings per start, in the process. Lynn struck out 76 and walked 26, giving up 56 hits and 3 home runs. Batters hit .211/.288/.320/.607 off him. Batters had a .279 BABIP in those 12 games.
As the weather warmed up, so did batters hitting against Lynn. In his next 14 contests, Lynn went just 7-7 with a 5.02 ERA. He threw 86 innings, just over 6 per start, in the process. Lynn struck out 77 and walked 35, giving up 88 hits and 6 home runs. Batters hit .271/.348/.385/.732 off him. Batters had a .332 BABIP in those 14 games.
Why was Lynn giving up more hits and thus more runs in those last 14 games? He threw nearly the same amount of innings per contest. He struck out slightly less people and walked a few more. He gave up twice as many homers. Why?
In games 1-12, Lynn threw 60.58% 4-seamers at 93.03 mph; he threw 17.26% sinkers at 92.14 mph; he threw 11.87% curveballs at 79.53 mph; he threw 8.38% cut fastballs at 86.61 mph (the speed indicates to me that it is a slider that doesn't move very much laterally); and he threw 1.91% change ups at 85.29 mph.
In games 13-26, Lynn threw just 45.66% 4-seamers at 93.34 mph; he threw 22.21% sinkers at 92.36 mph; he threw 16.72% cutters at 87.95 mph (different order there); he threw 9.30% curveballs at 79.31 mph; and he threw 6.11% change ups at 85.26 mph.
Lynn has drastically changed his arsenal by throwing just 3/4 the same amount of fastballs, adding 5% to his sinker totals, doubling the amount of cutters he threw, over tripling the amount of change ups he threw and dropping his curveballs by a couple percentage points.
It really is a change of two seasons for Lynn. He is a completely different pitcher than he was when he was more productive earlier in the year. Unfortunately, that does not include today's 9 hit, 1 BB, 1 HR, 5 K, 7 inning affair.
(Thanks to brooksbaseball.net for the information!)