“Does Bill James Even Like to Watch Baseball?”

Projecting players is a tough business. Because of the natural tendency to ignore injury risk and reversion to the mean, our instincts lead us to over project. We have seen this with the fans who are about half a win high (and a full win high projecting players on their favorite time) and who are generous with projected playing time.

So it is easy to look at projections and think they look low, and so we should give people a pass when they say so. But when they say so and in the process disparage the projector, I think it’s fair game to call them out. Here is a video of Bob Ryan and Joe Sullivan discussing Bill James’ projections for some Boston Red Sox players (h/t Repoz). Ryan and Sullivan were aghast that Bill James would project Jon Lester for just 14 wins in 2011, joking that their colleague Dan Shaughnessy would say “Bill James doesn’t even like to watch baseball!” and that if James actually watched Lester pitch he might think differently. Ryan claimed that Lester is a 19-game winner for the foreseeable future.

Lester is a great pitcher and won 19 games last year, but to win 19 or more games everything has to break just right. The pitcher has to pitch lots of innings, do so at a relatively high level (or be astronomically lucky), get good run support, and then have a bullpen hold the lead.

Can we expect that all out of Lester in 2011? First, let’s look at projecting innings pitched. He has pitched just over 200 innings in each of the past three years, which gives us a quick jumping-off point. I looked at all pitchers who averaged between 190 and 210 for three straight years (i.e., had a total of between 570 and 630 IPs during three consecutive years) in the 2000s and then saw how many innings they had in the next year. I came up with 136 pitchers, and they averaged 170 IPs in the next year — a good 30-ish innings fewer than they had averaged over the previous three years. That is aging and reversion to the mean. Lester is younger than this group on average so maybe you can expect him to have a few more than 170 IPs, but that number might be a safe guess for how many innings he will throw.

But maybe you are supremely confident in Lester’s talent and durability. Say you are sure he will have over 200 IPs and an ERA under four. How many games should we expect him to win? I found 188 pitchers who meet these criteria in a season since 2001. How many wins did they average in those seasons? Fifteen. Even pitchers who pitch well over a full season do not necessarily get near 19 wins (the lowest total was Brandon Webb’s 2004 season with just seven wins in spite of his 208 innings at a 3.59 ERA).

Sure, the Red Sox are an excellent team and will give Lester way more support than the 2004 Arizona Diamondbacks did Webb. But wins are fickle: Matt Garza won only eight games for the solid 2009 Tampa Bay Rays when he pitched 203 innings with a 3.95 ERA and last year Tommy Hanson won just ten games on a good Atlanta Braves team while pitching 202 innings with a 3.33 ERA.

The point is you cannot assume that Lester is going to have another 200-inning season, and even if he does, you cannot pencil him in for 19 wins (look at his 2009 season: 203 innings, a 3.41 ERA, and just 15 wins). That is why Bill James, who I am sure loves to watch baseball, projects 14 wins for Lester.