Domonic Brown is on some kind of home run streak. He has hit nine home runs in his past 11 games to move into the National League lead in the category with 17. What's more, in his past 27 contests, he has 12 homers -- precisely the number he hit in 147 games from 2010-12 combined.
It's this sudden power surge -- the topic of one of colleague Eric Karabell's Monday blog posts -- as well as that of American League home run leader Chris Davis (20) that has many a fantasy owner wondering, can these guys possibly keep up the pace? Brown, after all, finds himself on track for 47 homers, and Davis 56. To put those numbers into perspective, those 47 homers for Brown would be more than he had hit in his career at the Double-A, Triple-A and big league levels (43 -- 18, 13 and 12, respectively). Those 56 for Davis would be only four shy of his entire total from 2009-12 combined -- and those came in 356 games.
ESPN Stats & Information provided an insight to Brown's homer binge that casts doubt on his ability to maintain such a pace: All 17 homers this season have been pulled to right field, resulting in an average home run distance of 378.4 feet. Raul Ibanez (374.5) is the only other player with at least 10 homers this season and an average home run distance of less than 380 feet, and Curtis Granderson (43 homers, 383.1 feet average distance) was the only 30-homer hitter in 2012 with an average distance of less than 390 feet.
But it's not mere home run distance that separates facts from flukes. If that were true, then Chris Davis, with his 409.8-foot average, might look like an outstanding bet for 56. Instead, examine the slugger's performance in several underlying categories: his home run/fly ball percentage, his fly ball rate and his percentage of hard-hit fly balls -- heck, let's toss in home run/fly ball percentage on those hard-hit flies.
Home run/fly ball percentage has become one of the more popular indicators of fact-or-fluke home run analysis in fantasy baseball the past half-decade, much the way BABIP is now all the rage when addressing batting average. And just like BABIP, it should not be construed as a one-size-fits-all measure of luck; that is the very reason for including the other categories in such an analysis. Remember, no two fly balls are struck the same, as anyone who has watched Ben Revere and Jose Bautista will tell you.
To explain briefly what home run/fly ball percentage calculates, it's the percentage of flies -- meaning charted fly balls and only line drives that are home runs -- that clear the outfield fence. The league average in the category this season is 10.5 percent, just as it was in 2012, but prolific sluggers have been known to reside in the 20-22 percent range, just as "Punch and Judy" hitters typically rest around 6 percent (if not lower). The idea is that as statistical samples expand, meaning as the season progresses or by comparing one year to another, a player's number in the category regresses to the mean and his homer output adjusts accordingly.
Here's the kicker about home run/fly ball percentage: There's actually a much stronger correlation between fly balls measured as "hard contact" clearing the fence than fly balls as a whole; 44.2 percent of fly balls charted as hard hit have become homers this season, and 42.6 did last year. So when you're looking for unexpected power surges, take a look at how frequently the player generated a well-hit fly ball when he put it in play.
The chart below isolates some of 2013's more intriguing sluggers, the minimums for inclusion being a full-season pace of at least 30 home runs, a .225 isolated power (slugging percentage minus batting average) or a 13 percent well-hit fly ball rate (meaning that at least 13 percent of the time he puts the ball in play it was a hard-contact fly ball).
"Pace" is the player's full-season HR pace. "WH FB%" is the player's percentage of balls in play that were fly balls judged as hard contact. "HR/FB% (WH)" is the player's home run/fly ball percentage only on fly balls judged as hard contact.
Suddenly Davis' power output looks more sustainable, doesn't it? Granted, his 21.2 percent rate of well-hit fly balls seems somewhat unsustainable, but when Davis strikes the ball hard in the air, he hasn't had unexpected results. After all, 10 qualified hitters had higher than a 60.6 home run/well-hit fly ball percentage in 2012, including Davis (68.6 percent). It's time to believe in his 40-homer ability -- something he appeared to possess during his early days with the Texas Rangers and has reappeared in Baltimore -- and a 50-homer season isn't out of the realm of possibility.
Brown, meanwhile, has been extremely fortunate on well-hit fly balls (85 percent), and he hasn't hit an exceptionally high rate of them in the first place (10.6 percent). To expect him to have an ability to place his drives in such precise spots -- such as the 330-foot measurement to the right-field pole at Philadelphia's Citizens Bank Park or the 369-foot marker in right-center -- at this frequency is asking a lot. Though a season of fewer than 30 homers seems improbable, it's not impossible. Any Brown owner should be pleased with every homer he or she gets from him beyond that plateau.
What the chart also does, incidentally, is help identify players who might have either benefited from good fortune in these categories or suffered from poor fortune. Here are two players who seem intriguing buy-low power sources:
Freddie Freeman, Atlanta Braves: Three home runs in his past six games might convince his owners that he's turning around his season, but the truth is that he's only scraping the surface of what might be 30-homer potential -- though that number probably should be scaled to games played, since he spent some time on the disabled list. Freeman continues to improve at making contact, his strikeout rate in the midst of a four-year pattern of decline to begin his career, and he showed with a 41.7 percent fly ball rate in 2012 that he knows how to drive the ball. A 31.6 home run/well-hit fly ball percentage is awfully low for a player who generates well-hit fly balls about 13 percent of the time.
Ryan Howard, Philadelphia Phillies: Argue that age (he's 33) or injuries are catching up with him, but if that were true, how is it that he hit home runs on 60.9 percent of his hard-hit fly balls in 2012? Howard's number in that category has plummeted this season, and you can't argue that it's the ever-shifting-toward-pitching Citizens Bank Park that's responsible; fellow lefty Brown has hit 11 homers there. Howard also has another trait that makes him an attractive trade target: He has a career slugging percentage 67 points higher after the All-Star break (.581) than before it (.514), and he has homered in 1.5 percentage points more of his at-bats in the second half (8 percent) than the first (6.5 percent).
Here are two players who you should probably sell, based on what appears to be an unsustainable hot start in the homer category:
Mark Trumbo, Los Angeles Angels: If we're talking about first-half/second-half players, Trumbo is the opposite of Howard, the player you shop based on his trends. In his two full big league seasons, he has turned in .247/.275/.469 (2011) and .227/.271/.359 (2012) second-half triple-slash rates, each of those representing substantial drops in production from his first-half numbers. With Trumbo, though, it's that his home run/fly ball percentages are somewhat high in both regards. He has a 21.7 percent number on all fly balls and 76.5 percent when he makes hard contact on fly balls. Those are both bound to regress.
Carlos Beltran, St. Louis Cardinals: He managed one of the best home run/fly ball percentages in his career in 2012 (18.5 percent) and has somehow improved that number this season (18.8 percent). Using FanGraphs' numbers, which date to 2002, Beltran's stats in those categories would represent his second- and third-best single-season numbers. What's more, his 81.2 percent homer rate on well-hit fly balls this season is well above both the league average and his 2012 number (64 percent). Now 36, Beltran brings with him some risk, and he's not in the best ballpark for power.
The threat of PED suspensions
With news breaking Tuesday that as many as 20 players -- including No. 3-ranked Ryan Braun -- could be facing suspensions, some potentially as long as 100 games, the fantasy baseball rankings have been thrust into a temporary state of flux. I haven't adjusted my rankings to account for this threat of suspension for two reasons: (1) I don't consider myself qualified to judge the likelihood of suspension, length of suspension or possibility of successful appeal, and (2) I think the impact on rankings is fairly obvious: A 100-game suspension would extend beyond the end of the season, meaning players subject to one would simply fall out of the top 150 rankings.
Players reportedly under scrutiny are marked with an asterisk in the rankings below.
TOP 150 HITTERS
Note: Tristan H. Cockcroft's top 150 hitters are ranked for their expected performance from this point forward, not for statistics that have already been accrued. For position-specific rankings, see the "Pos Rk" column; these rankings can also be seen split up by position.