Because so much goes into a good performance, pitchers tend to be very hard to predict on a game-by-game basis. Not only does the pitcher's actual ability from game to game, but so does the quality and consistency of the umpire, opposing hitters and defenders behind him.

Because their performance can fluctuate so greatly, and because there seems to be so many quality starters out there, many Fantasy baseball analysts will tell you it doesn't make much sense to invest heavily into your pitching staff on Draft Day. There are always Jacob deGroms and Garrett  Richards out there, and every season some elite pitcher is struck down by injury or a case of the yips and falls off the map.

Clayton Kershaw is supposed to be the exception. With Kershaw, you are paying for the absurd high's -- those 14-strikeout shutouts -- but also for the absence of the low's. He just doesn't have those kind disastrous starts that can torpedo an otherwise flawless Fantasy week.

Last season, for example, he never allowed more than 10 earned runs during any stretch of three starts, and seven of those 10 came during one outing. This season, on the other hand, Kershaw has already had three-game stretches of 10, eight and nine earned runs; that's not what you invested a first-round pick in.

With a 4.26 ERA through 44 1/3 innings, Kershaw has not come as advertised so far. Is there any reason to panic, or to consider him anything but the best pitcher in baseball still?

As with his AL Cy Young winning counterpart Corey Kluber, the answer is almost certainly a resounding "No." Kershaw almost certainly won't finish with numbers anywhere in the vicinity of the 1.77 ERA he posted a year ago, but there isn't much to suggest he has regressed.

First off, his surface peripherals are either improved or nearly identical to last season. His K/9 has raised from 10.85 to 11.37, his BB/9 has made a similar increase from 1.41 to 2.23, while his groundball rate has also moved a tick and a half in the right  direction. Add all that up, and Kershaw's xFIP is 2.18, nearly identical to the 2.08 mark he managed a year ago.

Of course, xFIP assumes most pitchers allow home runs at roughly the same rate, which is obviously not the case. For instance, Kershaw's career mark is 6.9, far better than the league average pitcher. This season, however, that has ballooned to 20.8  percent, by far the worst mark of his career. Is there anything to be concerned about as far as that  is concerned?

According to FanGraphs, Kershaw does have the highest hard-hit ball average of his career, at 33.3 percent. He is also recording infield flyballs at a career-low rate while giving up a ton of line drives, two indications that he isn't inducing quite as much weak contact as usual. We're  still talking about relatively low numbers of batted balls, so this could all be the result of bad luck, but Kershaw is such an important figure in Fantasy baseball,  it's worth looking a bit deeper.

Per, Kershaw's slider and curveball have been nearly impossible to homer off in his career, and that has been the case so far; he has allowed just one long ball on 319 combined pitches. However, his fastball has been an issue so far, as opposing hitters are batting .300 with a .190 ISO in 100 at-bats ended against the fastball.

Kershaw is still throwing the fastball in the mid-90's, and still getting tons of movement, so stuff doesn't seem to be the reason for his issues. Maybe it's command?

The first image is 2014, the second is 2015

Kershaw certainly seems to be leaving his fastball up in the zone a bit more, as illustrated by the lack of deep purple and red in the bottom half of his 2015 zone profile. Though it isn't always a perfect correlation for every pitcher, pitches in the higher bands of the strike zone tend to go for extra-base hits more often, and that has been the  case for Kershaw with his fastball. As good as he is, and as dominant as his fastball can be, even Kershaw has holes that can be exploited when he misses. 

Honestly, this is all nit picking to a certain extent; that's just about all you can do when faced with a player of Kershaw's greatness. He's had a handful of bad starts through early May, but is still third in baseball in xFIP and 15th in FIP, so it's not like there are grave flaws. If I was a betting man, I would take Kershaw against the field to finish as the best Fantasy pitcher from this point out, and you should definitely value him as such. You can't overreact to a relatively slow start for the best pitcher in baseball, and it's hard to imagine any Fantasy player would do so.

So, what's wrong with Clayton Kershaw? Just like with Kluber, the short and most meaningful answer is, "Nothing."