Which MLB pitchers are throwing their best stuff most often, and who shouldn't be?

Jake Irvin has been an average pitcher at best in his three MLB seasons, with an ERA of 107 and a FIP (Fielding Independent Pitching) of 114 .

The Washington Nationals righty has almost exclusively used three pitches: four -seam fastball, curve and sinker.

The award for the league's most balanced starter belongs to perhaps an unlikely name.

The top relievers tend to be more optimized (with lower Nash Scores ) than the top starters.

Some relievers do a better job of balancing their pitches than others.

Some pitchers are more likely to lean on their best pitches more without the same concerns about predictability that starters face.

Tommy Kahnle's lead pitch is a changeup (not a fastball) so effective that it's nearly four runs per 100 pitches better than the rest of his repertoire.

Ryan Helsley , Justin Lawrence and John Brebbia's primary pitches were far less effective than their secondary options.

Kenley Jansen's primary pitch is one solid pitch -- but they don't have much else to work with so any deviation worsens performance.