Scott Elbert’s 10.66 strikeout per nine ratio put him among the minor league’s elite last season – 8th best of the pitchers in our Top 100. That doesn’t mean squat.
It’s not every day that I pick up an entirely new lens with which to evaluate prospects. A few weeks ago I had one of those days.
For the past six months I’ve primarily gone by a combination of strikeouts per nine (K/9), walks and hits per inning pitched (WHIP), and HR per nine (HR/9) in my prospect ranking. My goal was to use these stats to distinguish the pitching prospects with the best stuff, command, and ability to keep hitters off balance.
I’m beginning to realize – thanks in large to Baseball America’s Matt Eddy – that while strikeouts per nine can be interesting to look at, the stat has two major flaws:
1) No one actually throws nine innings every start.
2) A pitcher who dances around the strike zone could wind up with a better K/9 than a pitcher who attacks the zone.
| Player | 06 K/PA | 06 K/9 | Level(s) |
| Yovani Gallardo | 31.6% | 10.91 | A+/AA |
| Jacob McGee | 30.9% | 11.49 | A |
| Phil Hughes | 30.7% | 10.36 | A+/AA |
| Matt Garza | 29.7% | 10.21 | A+/AA/AAA |
| Brandon Erbe | 29.4% | 10.44 | A |
| Scott Elbert | 29.1% | 10.66 | A+/AA |
| Homer Bailey | 28.4% | 10.16 | A+/AA |
| Franklin Morales | 27.4% | 10.46 | A/A+ |
| Adam Miller | 25.4% | 9.15 | AA/AAA |
| Nick Adenhart | 23.0% | 8.24 | A/A+ |
| * numbers are combined minor league from 2006 | |||
So what’s a better indicator of raw stuff, command, and ability to fool hitters? Strikeouts per plate appearance – or K/PA.
Exemplified
in the chart to the left, K/PA embodies elements of command as well as
stuff. It works as a much better tool for evaluating prospects than
K/9. (You can calculate K/PA by 1) Dividing the amount of hits a
pitcher gives up by his batting average against 2) Adding walks to the
number that you got in step 1 3) Dividing the pitcher's strikeout total
by the number that you got in step 2.)
Yeah, going from K/9 to K/PA is as much of a chore as switching to the metric system, but the world works on metric for a reason.
Notes about my ranking system
Though K/PA leaves me with two statistics that factor in walks, I don’t
think it will force me to alter my current formula for evaluating
pitchers – may just require some minor weighting tweakage. Also, I may
try going with batting average against rather than WHIP.
| Player | 06 HR/PA | 06 HR/9 | Level(s) |
| Brandon Erbe | 0.44% | 0.16 | A |
| Nick Adenhart | 0.48% | 0.17 | A/A+ |
| Phil Hughes | 0.91% | 0.31 | A+/AA |
| Yovani Gallardo | 1.01% | 0.35 | A+/AA |
| Matt Garza | 1.16% | 0.12 | A+/AA/AAA |
| Jacob McGee | 1.27% | 0.47 | A |
| Homer Bailey | 1.27% | 0.45 | A+/AA |
| Franklin Morales | 1.38% | 0.53 | A/A+ |
| Adam Miller | 1.42% | 0.51 | AA/AAA |
| Scott Elbert | 2.52% | 0.92 | A+/AA |
| * numbers are combined minor league from 2006 | |||
It should also be noted that I’m going to recalibrate
to HR/PA rather than HR/9, as well. I’m pretty sure that it’s going to
take years – if not decades – to help lead the anti-ERA charge, but I’m
also going to try to lean on ERA/GS and ER/IP from here on out.
Adam Foster is here to help if you're having trouble parting with K/9. You can email him at adamwfoster@gmail.com.