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John Mayberry Jr’s Strikeout Rate

John Mayberry started the season in AAA for the Phillies and eventually got the call to the majors. He has been a pleasant surprise by hitting 15 home runs in only 275 PA. He had shown power in the past, but a large K% was limiting his HR and AVG production.

In 50 plate appearances with the Phillies in 2009 and 2010, he hit fly balls 43% of the time. Of these flyballs, 30% left the stadium for a home run. This season’s numbers are similar with a 39% FB% and a 19% HR/FB%. His ability to hit home runs has not changed. He is good at it.

The problem for John was that he could not make contact with the ball. In all minor league levels, he struck out 22% of the time. It peaked in 2009 when it was at 26% in AAA. Since that point, he looks to have made an effort to bring the rate down. Here are his AAA and MLB K%’s from 2009 to 2011:

Year: AAA K%, MLB K%
2009: 26.3%, 38.3%
2010: 20.3%, 30.8%
2011: 18.9%, 18.5%

He has seen a steady improvement in his strikeouts. Using batted ball data, the change can be attributed to his contact % going from 68% and 55% in 2009 and 2010 to 77% in 2012.

Besides the increase in chances for home runs, he will also have a better chance of getting a regular hit. More balls in play will mean a better AVG.

The change from striking out around 25% of the time and 19% will be significant. Using 20% HR/FB%, 40% FB%, 7% BB% and 0.290 BABIP as constants, here are the HR and AVG values by changing the K% from 25% to 19%:

25% K%: 0.253 AVG, 33 HR
19% K%: 0.276 AVG, 36 HR

The increase in home runs is only 3, but his AVG improves by about 25 points. A 0.253 AVG is not Adam Dunn horrible, but it will be a drag on a fantasy team. The increase in AVG to the 0.276 will be closer to the average value (depending on league size). The extra home runs are just icing on the cake.

For John to be valuable next season, he will need to continue keeping his K% under 20%. If he is able to do that, his AVG will be higher and not be as much of a drain.