Charleston BB and K Rates

Written by Sean P | 15 September 2010

Here's your primer:

I wanted to take a look at BB% and K% for each level because it can give us a rough outline of a player’s strike zone judgment. Strike Zone judgment encompasses a player’s ability to avoid strike outs as well as draw walks.

Thanks to Jeff Sachman who did some work on translating amateur K%, we know that a strikeout rate of 25% in the majors roughly equals a 21% rate in single A ball. Of course we know that players are going to cut down on these rates as they get older and gain more experience- I don’t think anyone would blindly write off a top talent because he struck out a lot as an 18 year old in the Gulf Coast League. Also we may be running into sample size issues in the minors where most guys don't get enough PAs for BB and K rates to totally stabilize.

When looking at these graphs, make sure you take into account the age and experience of each prospect before rushing to judgment on them. The average K% in the Sal League among qualified batters was 23%, while the average BB% was 7.7%. Also, keep in mind the SAL favored pitchers this year by a good amount as you can probably tell from the average BB rate.

charleston_bb_and_k

Looking at this graph, I’m impressed with JR Murphy. He was essentially making his pro debut and although he didn’t have a great season (.255/.327/.376) the scouting reports about his approach at the plate seem accurate....Kyle Higashioka was another surprise for me. Not counting his 50 PAs in 2008, Higashioka has had above average strike zone judgment the past 2 seasons but awful results- .315 and .297 wOBA respectively…. Slade Heathcott didn’t really wow anyone this season (.331 wOBA), but I was impressed with the 19 year olds ability to get on base- contact issues for a first year guy aren’t out of the ordinary... Luke Murton had a pretty good season (.376 wOBA) and managed to cut down on the K% from last year…Zoilo Almonte also carried over his good work from 2009 before being promoted to Tampa where he ran into a wall. Interestingly, he had almost the exact same K and BB rates across both levels- 8% BB rate and 28% K rate.