April's Five Fastest Hitters

These five batters experience the highest raw positive variance in OPS in April compared to their career averages. Will they start strong in 2016, or regress?

The baseball season is a long, grueling test of one's endurance. Monthly splits in baseball are fascinating to consider, as conditions can truly affect how a player performs. Some hitters are wired to peak in the dog days of summer, when the air is thinner and pitchers often wear down after hurling a bunch of innings in sweltering conditions. Others pounce on their opponents from the get-go when a lot of guys are still making adjustments from spring training.

Weekly Rotation, a new feature on Yahoo Sports will regularly examine and rank five players, teams or events around the league. This week, we'll highlight the five batters who experience the highest positive variance in OPS in April compared to their career averages. These guys could start strong again in 2016 -- or perhaps they're due for some regression this month.

Note: All mentions of April statistics refer to career numbers in March/April. Hitters must have played at least 60 games in March/April to qualify.

5. Nick Hundley

Career line: .249/.301/.400 (.701 OPS)
March/April line: .284/.346/.453 (.798 OPS)

Nick Hundley was seemingly on the verge of falling off the Major League radar before last season as a catcher entering his 30s who didn't exhibit any standout skills. But the veteran leaned on a fast start in 2015 (.317/.369/.450 April slash line) to claim a full-time starting gig in Colorado, and he never cooled down while enjoying a career year at the plate.

The 32-year-old might be in for another hot start in 2016. The Rockies play 13 of their first 22 contests at home, where Hundley boasted an altitude-aided line of .355/.393/.563 last season. That's impressive, even at Coors Field. He hit a three-run homer Tuesday night. So far, so good.

4. Matt Kemp

Career line: .289/.345/.489 (.833 OPS)
March/April line: .319/.380/.552 (.932 OPS)

Matt Kemp has been tagged as a second-half hitter after consecutive strong finishes in 2014-15, but April has historically been Kemp's best month. Who could forget his stunning beginning to 2012 coming off a near 40-40 season?

It's what immediately follows April that plagues Kemp. He's recorded a .698 OPS in May, by far the worst monthly output of his career. His 2015 campaign followed that familiar pattern, as he logged a pitcher-esque .186/.225/.212 line in 29 homerless May contests following a torrid debut month for San Diego.

3. Jeff Mathis

Career line: .194/.254/.306 (.560 OPS)
March/April line: .232/.285/.399 (.684 OPS)

Jeff Mathis is almost certainly the worst hitter in the Majors, and perhaps one of the worst of all time.

The last time he reached base more times than striking out in a season was back in 2007, when Mathis was still viewed as a promising first-round pick. No position player who debuted after 1982 has accumulated as many plate appearances as Mathis has while posting a career OPS as low as his, according to Baseball Reference.

But honest to God, Mathis has resembled a real-life big-leaguer at the plate in 74 career April games. Heck, he even started off 2010 with a 10-game hitting streak that propped up a legitimately robust line of .324/.351/.500. Unfortunately, a wild pitch by Kevin Jepsen fractured his wrist and curbed that remarkable run, predating an all-too predictable descent by Mathis back into the depths of the league's hitting leaderboards.

2. Jed Lowrie

Career line: .257/.328/.410 (.738 OPS)
March/April line: .306/.396/.476 (.872 OPS)

Jed Lowrie had the best hitting month of his career last April, posting a .999 OPS in 18 games for Houston before a torn thumb ligament sidelined him until after the All-Star break.

Now back for a second stint in Oakland, Lowrie will be depended upon to help keep the A's afloat in the competitive AL West early on. Lowrie's three-year contract seemed quite team-friendly when it was signed, but that might not be the case if he can't rediscover the pop that produced 31 homers between 2012-13. He's off to a good start, with four RBIs in Oakland's first two games.

Lowrie's career slash line comes out to .246/.307/.396 if you remove the 126 games played in April. That's not so great for a guy who's regarded as an offense-first player, even if Lowrie will primarily man second base for the Athletics in 2016.

1. Derek Norris

Career line: .248/.325/.396 (.721 OPS)
March/April line: .328/.398/.475 (.873 OPS)

The current perception of Derek Norris is that he's a slightly above-average hitter for a catcher. Norris owes much of that perceived value to his production in April, which went a long way toward earning him his lone All-Star bid in 2014.

Norris owns a .873 OPS in April, yet hasn't scraped above a .732 OPS in any other month. The 27-year-old's BABIP in April is .383, compared to his overall career BABIP of .305. His career line outside of the season's first month is .235/.305/.384.

Surprisingly, monthly splits aren't the most divisive grouping of Norris' performance at the plate. That's because there aren't many MLB players whose individual success coincides with their team's more than Norris. He holds a .874 OPS in victories, compared to a paltry .538 OPS in defeats.

All of this is to say: if Norris, Kemp and the Padres don't burst out of the gates in April, their collective outlook for 2016 will be pretty bleak. That is, unless monthly splits are all a bunch of hooey.

Baseball: "April's Five Fastest Hitters"