Jon Lester's New Approach

Against the Mariners on Monday night, Red Sox starting pitcher Jon Lester tossed a one-run, complete-game effort. He was effective throughout, finishing at 119 pitches with 61 percent of them going for strikes, but it wasn't because he all of a sudden rediscovered the swing-and-miss in his game. Instead, Lester beat the Mariners by letting them beat themselves: with grounders.

Lester has not had the same kind of luck as in the past with missing bats. In 2009, Lester struck out 10 batters per nine innings pitched, posting the top K/BB of his career in the process. The next season, he punched out 9.7 per nine, leading the American League. Things started to slow down for him in 2011, though, with Lester striking out 8.5 per nine, and now, after six strikeouts in nine innings last night, sits at six per nine on the season.

That's a below-average whiff rate, and strikeouts don't take very long to stabilize, either. Lester has faced 211 batters, and according to research by Russell Carlton (formerly of Baseball Prospectus, and now with the Cleveland Indians), it takes around 150 batters faced for both strikeouts per plate appearance and grounder rates to mean something. It doesn't mean that this is who he is forever, now -- 150 batters faced isn't that many starts -- but it does mean he's hit a point where we shouldn't just automatically assume things will change for the better.

As for grounders, on the season, Lester is where he normally is -- right around the 50 percent mark. There was an effort to induce them against the Mariners on Monday night, though, as evidenced by Lester's pitch selection. Out of his 636 pitches thrown before his most recent start, just 100 of them had been sinkers (15.7 percent). Against the Mariners, Lester threw 63 sinkers out of his 119 total pitches, or 53 percent. That's the kind of difference that, even in one start, is difficult to ignore.

In his previous start against the Royals, Lester threw 108 pitches, just eight of them sinkers. His cutter got plenty of play in that start, but against the Mariners, he threw the pitch just twice. Lester has had trouble inducing swings-and-misses on his cutter this year, instead racking up his pitch counts when the opposition fouled the pitch off. It was also his least-effective offering for called strikes, and didn't get the whiffs of the similarly-low change-up. It's a pitch that's worked in the past, but overall, it's been problematic in 2012.

It's not the only offering with that issue, as Lester's curve -- once so good at inducing swings-and-misses -- has done so at a below-average pace this season. He threw 12 benders last night, with half going for strikes, two of those swinging. If he's going to start picking up more strikeouts, this is likely the pitch that will need to return to form. As he struggled with using it effectively in 2011 as well, though, we're talking about more than an early-season blip.

We'll need to see Lester do this more often before we know if this was a one start thing until he gets his cutter working for him again, but given his success Monday, you have to assume he'll give the sinker experiment a second round. He induced 10 ground outs against three in the air to complement the six strikeouts, and that (along with a double-play started on a liner) helped Lester scatter eight hits. Had he walked a hitter or two, things could have been more problematic, but he also looked more comfortable with his sinker in terms of control than he has with his other fastballs this year.

The one other thing worth mentioning is placement. Lester was focusing low, as well as inside and outside of the strike zone with his sinker, but he also left quite a few of the pitches up, and they were put in play. Had he been facing someone with more punch in their lineup than the Mariners, the results might not have been as attractive:

Lester's next start comes against the Phillies, and with the way they've been hitting, he'll get another chance against a weak lineup to work out the kinks in this approach. That's a positive, as he's not quite finished if he's in the midst of a transformation.

PITCHf/x data courtesy of Brooks Baseball and Texas Leaguers