(AP Photo/Beck Diefenbach)

After a marvelous 2013 campaign that featured a 1.03 WHIP and 2.77 ERA, it seems Madison Bumgarner has taken a small dip in 2014. While he currently holds a solid 3.14 ERA matched with a 1.14 WHIP, his lack of consistency raises eyebrows — the San Francisco Giants left-hander has nine starts this year in which he gave up at least four earned runs.

Looking at his peripherals is at first a mystery. Comparing each year shows consistent strikeout rates (24.8 percent vs. 24.3 percent), FIP (3.05 vs. 2.96), and even a much improved walk rate in 2014 (2.77 walks per nine vs. 1.97 walks per nine innings). The main difference is the luck factor: Bumgarner had a 2.51 BABIP in 2013, but carries a .304 BABIP in 2014 — his highest since 2011. Despite a seemingly worse 2014 campaign, Bumgarner is the same elite pitcher who thrives with his slider.

Since 2012, Bumgarner has nearly identical slider usage rates — 39 percent, 38 percent, 38.3 percent — and has accumulated large Runs Above Average marks in the process: 13.2, 13.1, and 8.8 so far in 2014. Here’s an example of his signature pitch against Jimmy Rollins from last Friday’s game:

It’s a beautiful pitch to watch. Rollins is trying to protect on a 3-2 pitch, and believes he’s seeing a well spotted fastball on the inside corner. As he commits to the pitch, the ball features late break toward Rollins’s ankles, making the pitch unhittable and sending Rollins back to the dugout.

You may have noticed that the slider clocked in at 90 mph, an unusually high velocity for a breaking pitch. Its average speed of 88.2 mph has earned it the fourth-highest velocity in the majors, behind Charlie Morton, Corey Kluber and Zack Wheeler. Match that with a sixth-place ranking for vertical movement and Bumgarner’s slider becomes one of the deadliest in the game.

Nick Pollack writes for Pitcher GIFs and can found making an excessive amount of GIFs on Twitter