Welcome to the bi-weekly Stuff report! I plan on posting this every 2 weeks to show off the Stuff metric (http://www.mikesonne.ca/baseball/22/), and answer the age-old argument – who has the best Stuff in baseball.

What is Stuff?

Stuff is an interaction between velocity, pitch usage, pitch movement, and change of velocity. Previous articles on the development of the stuff equation have found that it is significantly correlated with both K/9, WAR, and xFIP/ERA. The benefit of using the Stuff metric, is you could theoretically look at a pitcher’s arsenal in a bullpen session, and with the use of radar guns and spin trackers, could calculate their stuff. This has implications for both scouting, and rehabilitation.

How is Stuff calculated?

What is Stuff

How to interpret Stuff

These rankings are filtered in descending order, from the best stuff in the MLB to the worst. I have presented the raw values that went into the calculation (because these are more fun to look at than the z-scores). I have also provided the percentile for stuff – which is from 0 to 100%. If a pitcher has 95% stuff, that means that their stuff is better than 95% of all other major league pitchers. Percentiles are blocked in 1% increments, so that is why you may see more than 1 – 100% stuff pitchers.

Enjoy! Feel free to use these numbers on your site, your Twitter, or in arguments with your friends at the bar. Remember, it’s always better to win your arguments with science.

The Best Stuff

Starting Pitchers

Note – Starting pitchers had to make as many starts as there have been weeks in the season to be included.

Starting Pitchers – By Team

Relief Pitchers

Note – Relief pitchers had to make as many appearances as there have been weeks in the season to be included.

Relief Pitchers by Team

That’s the stuff report for now! Feel free to comment, or use these numbers – just throw me a shout out.

Twitter – @DrMikeSonne