As previously defined, the Factor12 Rating (F12) is an analytic measurement utilizing league average performance to compare the value of all MLB pitchers.

In laymen’s terms, F12 is a rating that takes all aspects of pitching into account. It produces a number on a scale of 0.000-infinity (theoretically), where the average pitcher’s value is 24.000.

For example, Justin Verlander opened the season at Comerica Park yesterday and dominated the Boston Red Sox for eight innings.

Verlander’s line of 8IP / 2H / 0R / 1BB / 7K currently produces a F12 Rating of 38.879.

Yet, what does the 38.879 really represent?….

Justin Verlander's F12 values thru 4/5/12

Through yesterday’s games, 78 pitchers have thrown 194.33 combined innings. Consequently, the average pitcher has thrown 2.49 IP (194.33/78) in 2012. Using the average performance in each of the 12 categories, a percentage value is calculated for Verlander.

The ten ratio statistics use a formula that produces a number with a fixed range (0.001 – 4.000).

The IP and SO-BB categories do not use a fixed range, so it is possible to accumulate more than 4.000 points. This is done to give starting pitchers proper credit for their workloads.

**The F12 Rating is simply the twelve stat values added together.

**The average pitcher would earn a F12 Rating of 24.000.

** F12 can be viewed as the percentage difference for each pitcher above or below actual MLB league average performance (F12%>AVG).

F12%>AVG is the percentage difference between Verlander's F12 and the league average (24.000)