In 2012, Tim Lincecum was not particularly good. Good is obviously a relative term, as many pitchers would do anything to be able to post a FIP of 4.18 and an xFIP of 3.82 (looking at you Luke Hochevar). For Tim Lincecum however, those numbers are out of the ordinary, and I'm going to look into why he may have taken a step back this season.
The first thing worth mentioning is a poor strand rate. Lincecum stranded just 67.8% of the runners he allowed on base this year, as opposed to a career number of 74.6%. One could attribute this to bad luck, but looking at his numbers they suggest that Lincecum has been less effective with runners on base,
Lincecum has faced 2146 batters with runners on base in his career. Over that stretch he has held batters to a .290 wOBA, and a triple slash of .211/.299/.344. In 2012 however, Lincecum faced 357 batters, giving up a .363 wOBA to those hitters, accompanied by a .254/.370/.434 triple slash line.
Lincecum has seen a dip in his control this season when pitching out with runners on, having his BB/9 jump from 3.5 up to 5.47. I believe this may come from a mechanical difference in Lincecum's delivery out of the stretch. 2012 Lincecum (top) turns his torso almost completely away from the batter, causing him to have to exert more effort to get the ball to the plate. 2009 Lincecum (bottom) does not do this, and instead is much more efficient with his torso rotation and therefore uses less effort to get the ball out of his hand. Not only has Lincecum used more effort, but he is not even reaping the benefits of the increased effort, as his fastball velocity is down from 92.4 mph in 2009, to 90.4 mph in 2012.
While the pitching out of the stretch may be an issue, it is not the one that jumps out the most when looking at the data. The first thing that I noticed was that Lincecum has been using his slider at a growing rate since 2008. Since 2008 he has used his slider 3.38% of the time, 6.7%, 9.58%, 29.42%, and 20.49% (chart below)
The alarming part about his increased slider usage, is that the pitch has not been particularly effective. As you can see in the chart below, the whiff/swing rate is worse than it was when he was in his peak form in 2008/09.
According to Fangraphs pitch f/x data, Lincecum allowed a wRC+ on sliders in 2008 of 7. He followed this number up with wRC+ of 6, 32, 61, and finally culminating in 116 this year. Obviously it is a flawed statistic in a sample like this one, so here are his BB/Ks from that span: 0.12, 0.07, 0.15, 0.12, and 0.51 this season. Both stats show an alarming ineffectiveness from his slider in 2012, which may be part of the reason why he struggled so greatly this year.
My last concern is his change-up, a pitch that used to be a staple for him against lefties. This year, opponents hit .265 off of Lincecum's change-up, which is nearly .100 points higher than the career batting average against his change-up of .178. Comparing his change-up command against lefties in 2010 to 2012, one can see that he was able to spot it low and inside better in 2010 than he can now. This season Lincecum really lacked the ability to spot the change-up low and in the zone, instead missing low very often, and even occasionally out over the plate.
So despite these issues, the Giants think that by using him out of the bullpen in the playoffs that his stuff can play up.
Taking a look at his pitch f/x data from his two relief appearances in the playoffs, we can see if the stuff is playing up to where the old Lincecum was.
First looking at his fastball, it averaged 91.02 mph this season. During his two relief appearances in the post-season however, he has averaged 90.9 (25 pitch outing on 10-7), and 91.1 (55 pitch outing on 10-10). The whiff rate on his slider has actually gone down 1 percentage point, from 18.21% to 17.39%. The vertical movement on his curveball is up however, putting up numbers of -8.22 (10-7) and -7.69 (10-10) as opposed to -5.98 for the season (small sample size and different stadium camera caveats apply).
It appears as though the fastball isn't playing up, and the slider has not been any more effective than it was in the regular season.
Looking at Lincecum we can project a bounce-back season if his strand-rate regresses, and his HR/FB rate goes down from 14.6% (especially with the help of AT&T).
All pitch f/x graphs are courtesy of BrooksBaseball.net