I recently compiled and processed data from all 2014 plate appearances made through June 15 against all pitchers in these leagues and therein generated a trove of statistical performance ratings on several noteworthy prospects. Some of that is presented below after I briefly explain how I evaluate pitcher performance.
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Method
Every pitcher in the league gets charged with the number of runs shown in the table for each such event they have allowed in 2014 (after correcting for ballpark/stringer-related biases in event type classifications); those run values represent what each event is typically worth in the league.
The starting pitchers of the league then get ranked from best to worst at runs avoided per batter faced; the corresponding performance rating of a pitcher is termed their Performance Score. An Age Score is also computed to quantify how young the pitcher was versus other league starters; this parameter is used purely as a frame of reference when evaluating a pitcher's performance rating.
Each score is expressed on a 20-to-80-style scouting scale where 50 is league average, scores above 50 are better than average, and any 10 points equals one standard deviation; percentiles are also provided to show what percentage of league peers were beaten on the parameter.
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Results
The tables that follow will only include pitchers who faced at least 100 batters in the league in 2014 while averaging at least 10 batters faced per game. Scores in green beat league average by at least one standard deviation while those in red trailed it by at least one standard deviation. Asterisks denote lefthanded throwers.
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California League
Here are the top 20 performers of the 73 qualifiers who met the 100+ batters faced, 10+ batters per game criteria.
And below are the results of other pitchers who were either graded by John in the most recent Baseball Prospect Book or rated at least one standard deviation younger than the average league starter.
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Carolina League
Here are the top 20 performers of the 55 qualifiers who met the 100+ batters faced, 10+ batters per game criteria.
And below are the results of other pitchers who were either graded by John in the most recent Baseball Prospect Book or rated at least one standard deviation younger than the average league starter.
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Florida State League
Here are the top 20 performers of the 77 qualifiers who met the 100+ batters faced, 10+ batters per game criteria.
And below are the results of other pitchers who were either graded by John in the most recent Baseball Prospect Book or rated at least one standard deviation younger than the average league starter.
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