Pitchers who added something new

Braves left-hander Paul Maholm has used a slow curve to his advantage this season. Kim Klement/US Presswire

Every year, a few pitchers add a new pitch to their in-game arsenal after working on it during the winter or in spring training. Sometimes, the new pitch goes nowhere: It doesn't produce results and is quickly abandoned, or it lingers but fails to make an appreciable impact. Other times, it helps a pitcher achieve some specific goal -- such as limiting opposite-handed hitters -- but doesn't propel him to much greater heights. And every now and then, a new pitch transforms a pitcher into something far superior to what he was before. For example Mike Scott's splitter, Esteban Loaiza's cutter, or, more recently, Jason Hammel's sinker, which he added to great effect in 2012.

According to the custom PITCHf/x-based pitch-type classifications provided by Harry Pavlidis of Baseball Prospectus and Brooks Baseball, five pitchers have already unveiled new offerings in 2013. It's too soon to say for sure whether they'll all be successes, but a small sample often can reveal more about a single pitch than it can about a player's overall performance. Here's an early assessment of each one.

Paul Maholm, Atlanta Braves
Pitch: Slow curve

This might be more of a novelty than a new pitch; Maholm's slow curve isn't going to turn the league-average innings-eater into an ace. However, it does seem to be something new. Maholm's regular curve averages 73.4 mph, so it isn't exactly speedy. But the slow curve averages only 62.3 and can dip down into the 50s. So far, he has thrown it four times: twice to start an at-bat and twice with two strikes. Three of the four slow curves were delivered to southpaws.

Maholm's four-seamer has lost a few ticks in the past few years, so maybe he just wants to give hitters a look at something even slower. Maybe he's hoping for the element of surprise. Whatever the thought process, it's working so far. Maholm's four slow curves have resulted in two balls, a weak grounder to first, and, much to Chase Utley's dismay, a strikeout looking.