In fantasy baseball, everything is always about trends and patterns. Following batter-vs.-hitter match-ups and analyzing who does well during certain times of the year is critical to creating a solid lineup throughout the season.
Unfortunately, many players who are currently having great seasons may falter based on their career statistics and, more specifically, their post-All-Star break numbers.
Although Brennan Boesch has been playing well for the Detroit Tigers, if last season is any indication, he will eventually slow down considerably.
Currently batting .282 with a .344 OBP and nine homers, Boesch had been batting .342 at the mid-way point of 2010. Unfortunately, his struggles after the All-Star break were significant.
During the second half of 2010, Boesch bat just .163 with a .237 OBP and had just two home runs.
He's still quite young, and last season could just be an anomaly, but it's something to pay careful attention to if he begins slumping later in the season.
Michael Young has been a critical part of the Texas Rangers organization for a decade and is having an impressive season thus far.
He's currently batting .307 with a .347 OBP and 43 RBI.
However, last season, before the All-Star break, he was batting .301, but only managed a .262 average during the second half of 2010.
Young has shown in the past that he is capable of playing well after the All-Star break, but in two out of the last three seasons, he has struggled in the later months.
Carlos Quentin is having another monster year, evidenced by his current .560 slugging percentage. He's batting .266, but more importantly, he has a .365 OBP and 17 home runs.
Unfortunately for those who have Quentin on their fantasy team, his numbers are extremely similar to last year, when he was much less productive in the second half. His statistics went down in every category, but most significantly, his slugging percentage dropped over 100 points, and after 19 homers in the first half, he hit just seven in the second half.
Based on his career numbers, he is over-performing and may slow down around the All-Star break.
Ben Zobrist is quietly putting together a solid season for the Tampa Bay Rays. His .263 average and .338 OBP, along with his impressive power this season—20 doubles, four triples and nine homers—are all a significant improvements over last season.
Still, playing in just his third full season at second base, Zobrist is an uncertainty come the All-Star break. His numbers during the second half of last season were pretty dismal—.177 average and .292 SLG. Obviously affected by his inability to get on base, he also only managed to steal five bases.
The Los Angeles Angels' Erick Aybar is rebounding well from his disappointing 2010. He's currently batting .287.
Unfortunately, last season started off similarly. Aybar batted .283 with a .340 OBP before the All-Star break and had just a .206 average with a .253 OBP afterward.
Aybar is currently playing above his career averages, so be cautious if he starts to slow down.
Before he his the disabled list, Jason Kubel was having quite the season for the Minnesota Twins—batting .310 with a .355 OBP and .465 SLG.
Still, after hitting at least 20 home runs in the last three seasons, Kubels current season total sits at just five. And with just 30 RBI and 20 runs scored, he's producing less as well.
The loss in power may be worth the increase in batting average, but his numbers from last season are just too significant to ignore. He hit just .249—.231 after the All-Star break in 2010.
In addition, Kubel's career average is .274 and he's never ended a season above .300, so it's likely his numbers will drop.
For the last two seasons with the Chicago Cubs, Alfonso Soriano has been struggling to replicate the power and batting average he had in his younger years. In his last three seasons, he's failed to break the 30-home run mark, something he'd done five times between 2002 and 2007.
In three out of the last four campaigns, he's also failed to maintain his average from before the All-Star break through the remainder of the season.
Soriano is a big name, but unfortunately, he's lost a lot of what made him so popular in the first place. For example, he hasn't stolen a single base this season and only had five last season. Before he came to Chicago, he had stolen 40 bases three times and 30 bases twice.
I don't think there's anything that could be done to convince someone that Matt Kemp isn't worth holding on to for the rest of the season. He's an absolute beast right now—.335 average, .420 OBP, .638 SLG, 20 HR, 56 RBI, 16 SB.
There's nothing he isn't doing. He's hitting for power, hitting for average, getting on base and then stealing bags when he's there.
Still, there may be some cause for concern as the season goes on. In both 2010 and 2009, Kemp's average, ability to get on base and power all dropped significantly after the All-Star break.
In 2010, he hit .261 for the first half of the year and just .233 for the second. In 2009, he hit .320 and then just .270. It wasn't just his average either—on-base percentage and slugging went down as well.
However, Kemp is still going to be more productive than the majority of the league, even when he's playing under his potential.