I could preface this post with a nice fluff paragraph or two about the importance of home runs to a fantasy squad. But honestly, that's pretty well known. So let's dive right in.
With home runs driving much of the fantasy value of a player, it's important to dig deep when projecting how they'll hit this season. I'm going to run through a handful of players to illustrate different approaches and statistics we can use to predict home run rates, and along the way provide some draft advice on those players.
This first concept is pretty obvious. You're simply asking, "has he done it before?" If you pardon the crude graphic work, but we can easily illustrate that White Sox first baseman Adam Dunn may be the most consistent slugger in the majors over the last handful of seasons:
(Note that the y-axis on the left corresponds to the two rate stats, fly ball percentage (FB%) and home runs per fly ball (HR/FB), while the y-axis on the right indicates the number of home runs. The key takeaway is simply the level-ness of the lines.)
Unless you have some profound scouting insight, any projection too far out of Dunn's usual totals would be totally unfounded, because nothing has changed in the statistical record, and he's not old enough at 31 to worry much about age. In fact, with his move from the Nationals to the White Sox, his new home park yields 25% more home runs than his old. Keeping in mind he only plays half his games at home, that's not incredibly substantial, but he holds a good chance to break though his 40-home run "ceiling" by three or four if he maintains his consistency. You'll know what you're getting with Dunn on draft day.
To help explain why I selected to display those particular stats in the above graph, let's look at Toronto's Jose Bautista, an epitome of inconsistency. Bautista, who exploded for 54 home runs last year, hadn't topped 16 home runs in any of the four seasons leading up to 2010. What happened?
First, over half of Bautista's balls-in-play were fly balls last year - 54.5% to be exact. In 2009, that rate was just 42.1%. It's been publicized that he altered his mechanics and plate approach slightly, and I believe it manifested itself most in his FB%. If he keeps that up, he's launching an extra 50+ fly balls per season, and we all know hitting a fly ball is a prerequisite to hitting a home run.
Second, Bautista saw a spike of 9.4% in his HR/FB rate, propelling him from slightly north of league average up to 21.7%, the second highest in baseball. What does this mean? Well, it could indicate he added muscle, quickened his swing, or did something to help him hit the ball further, resulting in more of his fly balls landing over the fence rather than at the warning track. But his spike is so unique that if we dig further into the data, there's a good chance some plain old luck was involved.
Sure enough, 13 of Bautista's home runs cleared the fence by less than 10 feet. He was a couple wind gusts from only a 31 home runs season - still a good story, but far from league-leading numbers. If you look at the data across the league, HR/FB rates indeed fluctuate year-to-year for hitters, despite the player not really performing any different. He simply hit a few extra 390-foot fly balls to the deepest part of the park instead of down the line and in the seats. Or vice versa, as with Bautista.
What that means for Bautista is his HR/FB rate should come down, barring additional luck. If it were to drop to his career rate of 13.8%, a fair estimate, he would be in line for a drop to 34 home runs next year. A home run total in the low-to-mid-30's is still nice from a player who qualifies at third base and the outfield, but it might be best come draft day to let the guy who's expecting 50 from him again to reach for him. Not to mention, lost in the power debate is his career .244 batting average.
As mentioned above with Adam Dunn, a change in a home park can have big effects on some hitters. Adrian Gonzalez, moving from San Diego's hitter graveyard, to Boston's Fenway Park, would appear to be upgrading his facilities. In fact, Fenway yields nearly 50% more home runs to left-handed hitters than Petco Park, despite being below average itself.
However, it's important to note that Gonzalez is a spray hitter. He actually hit more home runs to left field last season (10) than he did to right field (9), which is unusual for a left-handed slugger. And of those ten homers he hit to the opposite field, only one went over 400 feet. The 37-foot Green Monster in left field at Fenway could give him some trouble, resulting in a bigger doubles spike than a home run increase. For instance, when Adrian Beltre moved into town, he only hit a couple extra home runs than he was hitting in a typical season with Seattle. However, he finished 2010 with the American League lead in doubles with 49.
The following are a handful of other players with statistics that stand out, and how those numbers might affect your draft strategy.
2B Chase Utley, PHI - Utley saw his home run total fall from 31 to 16 last season, a surprise considering he was nearly as consistent as Adam Dunn over the prior five years. The drop was precipitated by a fall in his fly ball rate, an odd development, as that number usually stays quite consistent for hitters. Given his track record, we can probably assume that will rise back to normal levels, especially considering he will want to prove he hasn't lost his power stroke. Don't shy away from him on draft day because you question his power, but you might want to considering the depth at second base.
SS Hanley Ramirez, FLA - Ramirez looked like a perennial 30-home run threat a few years ago, but has "only" hit 45 over the past two seasons. He's supposed to hit more as he hits his prime, so shouldn't we expect him to rebound? I don't necessarily think so. His 2007 total of 29 was driven by a spike in FB%, and his 2008 total of 33 was driven by an even larger spike in HR/FB rate. Both are outliers on his statistical record, and as such shouldn't be expected to repeat. But Ramirez will still produce a great batting average, 20+ home runs and 30+ steals. With the dearth of good shortstops this year, he shouldn't last past the fifth pick.
1B Derrek Lee, BAL - Lee fell from 35 home runs to 19 last season, which may rightfully scare off potential suitors in fantasy drafts this spring. Sure, Oriole Park at Camden Yards is slightly better for home runs than Wrigley Field, which is a good hitter's park in its own right, but Lee's drop-off may simply be due to age catching up with him. There were no firm statistical outliers last year that we can expect to rebound - his HR/FB rate was just 4.4% less than his career rate, a decline expected from a 35-year-old hitter. Lee is a health risk, and with every other team in your fantasy league getting power from first base, there are probably safer bets available around his draft slot.
OF Corey Hart, MIL - Hart went from dangerously close to being released last spring to a 31-home run season and a three-year contract extension. Luck has played a role in Hart's fluctuating numbers, but in this case it's been the absence of luck that made him look bad. In 2009, Hart hit just 12 home runs. All 12 would have been home runs in over half the ballparks in the major leagues. Each one was earned, while he watched his teammates and opponents sneak one over the fence with frequency. In 2010, seven of his home runs were of the luckier type, a much more typical ratio. Hart is also deceptively speedy, with two 20-steal seasons in his past, and has a new manager that likes to run. If others in your league are weary over his appearance of inconsistency and let him slip in the draft, jump on him in the middle rounds.