When it comes to projecting K/9, I’m not going to bust out any scientific formulas here. I’m not that big of a sabre nerd. Frankly I think some ppl take it too far, trying to use mathematical equations on everyone. This just isn’t possible, people are unique and situations vary too much to be doing this. I just busted out an uncommon amount of common sense using Fangraphs numbers. Basically I ask myself if a player’s stats will improve, remain stable or decline.
When it comes to roto leagues, I prefer using k/9 rather than total Ks. It’s just math. The things I look for when trying to project k/9 are O-Swing%, O-Contact%, F-Strike%, Pitch Values and Velocity, Pitch Type usage and control of the strike zone.
Rookies are a little different as their experience in MLB is limited so I don’t have a lot of info to work with. Jumping levels year to year also complicates matters. You cannot simply extrapolate minor league numbers like Bill James seems to do. I’m beginning to wonder if that guy is an actual person or a robot similar to Deep Blue.
O-Swing%: making batters swing outside the zone is good. 2009 league avg: 25.1%
O-Contact%: the percentage of O-Swings that make contact, less is better. 2009 league avg: 61.8%
F-Strike%: first pitch strikes, creating a pitcher’s count: 2009 league avg: 60.0%
Pitch Values: are the pitches getting better? worse?
Pitch Type Usage: I generally look for the pitches with movement, esp sliders
Control of the Strike Zone: bb/9, Zone %, F-Strike%
Other Factors: age, experience, team/league change, injury history, etc
I’ll try to find a good example… how about the MDS endorsed Gavin Floyd
Through 2007-2008 (276.1 IP) Gavin’s k/9 was 6.31, but in 2009 it jumped to 7.60. So what happened? He didn’t use his slider much in limited time with the Phillies, but he began throwing it with the Sox and the usage has increased each year since (16.8%, 20.6%, 26.9%). The jump in slider usage has come at the expense of his fastball. This makes me happy. Not only that, but the value of the pitch is getting better. It’s gone from a negative value (-2.2) and turned into a good pitch (7.5 runs above average). With increased slider usage comes a better O-Swing% and O-Contact%, resulting in more k/9. His O-Contact% dropped from 62.3% in 2008 down to 53.9% in 2009. This is a significant jump. Now while I wouldn’t expect that number to be that low next season, it is important to remember that his slider usage and value is trending upward so I would expect something near 55-56%. Gavin’s control of the strike zone also improved, slightly. His bb/9 dropped from 3.05 to 2.75, F-Strike% was a smidge better (55.4%, 59.9%, 60.0%), but his Zone% did drop from 51% in 2008 to 48.2% in 2009. The velocity on his fastball, slider, curve n changeup did improve slightly to career highs. So what’s this all mean? My brain cave is telling me Gavin has got it going on and I would expect his jump in k/9 to be real. His O-Contact% may rise, but not to a point where he would regress to 2008-2009 levels. I have him projected at 7.4 k/9, similar to Matt Cain.
Floyd is 27 years old and will be entering his 3rd full season in the Sox rotation, which generally seems to be the point where pitcher shows improved command. His pitches are getting better and he’s using his slider more. I think his improved k/9 is sustainable. He isn’t expensive and nobody seems to be talking him up. This is someone I want on my teams.
When you look at a decrease or increase in k/9, you gotta dig deep and figure out what happened. Did the pitcher change up his arsenal? Did he improve a certain pitch? Is the pitcher using his breaking pitches more/less often? Was his O-Contact% lucky or unlucky? Is he losing/gaining command of his pitches? Is he throwing first pitch strikes more/less often? You cannot use some sort of quantum physics equation here, figure out what’s going on and use some common sense.