This is the never ending concern for the 2010 Giants season. I have been meaning to look further into it everyday and today I have gotten around to pulling all the pitch f/x data that is available in Tim Lincecum starts.
The data is complete starting with the 2008 season so this is the starting point for everything and luckily for us this is also Lincecum's first full big league season so it gives us a very nice baseline to work with.
The results are not a surprise. Lincecum has lost velocity, in 2008 he had an average fastball of 94.1 mph, in 2009 his average was 92.4 mph and so far this season he has averaged 91.2 mph. However it might be a little unfair to end our analysis right here because there is so much more that we can look at from this information.
The first thing that really jumps out at me is how much velocity Lincecum has lost over the course of the season and how that has changed over the 3 seasons. In 2008 and 2009 Tim started out throwing gas and lost significant velocity by the end of the season. His April averages were 94.95 mph and 92.44 and his September average was only 93.73 and 91.44 a loss of 1.22 mph and 1 mph each.
This season his velocity has been much more constant. Tim's April average fastball was 91.4 mph and his fastball in his last 5 starts has been 91 mph a drop of only 0.4 mph so far this season.
The trend lines for each season tell us the same story; Tim has lost velocity from the start of every season to the end but has done so at a decreasing rate. The slope of the linear fitted lines has fallen each season, in 2008 he lost 0.0479 mph per game, in 2009 he lost 0.0249 mph per game and this season he has lost 0.0148 mph per game.
The other thing that is really interesting is that there is a pretty significant difference in velocity at home versus on the road. At home over the 3 season stretch Lincecum has averaged 92.09 mph and on the road over the span he has averaged 93.19 mph. I can't tell you why this is the case but it is something that is interesting and may lead to some further examination.
All of this being said there is no reason to expect that Lincecum can not continue to be an excellent pitcher. It might be too much to expect a Cy Yong award every season but that in itself is asking for a whole lot. The days of averaging 94+ mph are gone and we will have to live with that and fond memories of the days that he lit up the radar gun. The one thing that puts me at ease is that the rate of decline has slowed and I hold some optimism that for atleast the next few seasons expecting something along an average of 91-92 mph is not too much.
Without further ado here are the very velocity charts.
The following is Timmy's overall average fastball from each game he has started since the beginning of the 2008 season.
The next graph is his home fastball speeds.
And finally we have the road fastball speeds. The numbers here are all about 1 mph faster then the averages from the AT&T park readings.