Jim Thome has been plowing his way through the all-time home-run leaders in 2010. He began the year with 564 career dingers, one ahead of Reggie Jackson for 13th all-time, but with his 23 bombs on the year has worked his way past Rafael Palmeiro (569), Harmon Killebrew (573), Mark McGwire (583) and, most recently, Frank Robinson (586); now Thome sits in eighth. Unless he has a monster 2011, that's the end of the line, as the next batter in front of him is the still active (and much younger) Alex Rodriguez. Sammy Sosa sits at 609, meaning Thome may need more than one season to surpass him.

The first thing that came to mind when Thome passed McGwire was that Big Mac, who isn't that far removed from his playing days, is one more top-10 entrant away from being bumped off the list. There was a time when the words home run and McGwire were synonymous, so this turn of events, so soon after his retirement, strikes me as odd. Baseball Reference was able to sate my curiosity regarding who may pass McGwire and displace him from the leaderboard. Manny Ramirez is the most significant present-day threat at 554, good for 14th all-time, but if he fails to reach, there is no one else until Albert Pujols makes his way there and he is 47th with 405. Everyone in between the two—Carlos Delgado, Chipper Jones, Vladimir Guerrero, Jason Giambi, and Andruw Jones—are too old or have slowed too much to make a run. Scroll a little further, though, and Adam Dunn comes up at 79th all-time, tied with Dick Allen, with 351 homers at the spry enough age of 30.

Dunn is likely heading downward from his peak, but 351 homers is a large number for a 30-year-old. Is it large enough that Dunn is a threat to enter the top 10 in homers? Today we'll take a look at what his future may hold and see if he has a shot at cracking one of baseball's most cherished leaderboards.

First things first—2010 isn't over yet, but it's almost over, so let's add in Dunn's expected homer total for the rest of the year, per PECOTA, giving him 39 on the season (four more) and 355 for his career. As for predictions for future performance, we can use Dunn's 10-year forecast from this year's PECOTA projection. Given he has already played through 2010 though, we can cut those numbers out, making it effectively a nine-year forecast, from his age-31 season (2011) through age-39 (2019).

Over this time period, PECOTA thinks Dunn will amass 3,498 plate appearances and 192 additional homers, giving him 547 for his career. That's well off the pace he needs to reach the top 10, but there are a few things I want to go over here before we call it quits. That PA figure is low because it is assuming Dunn will miss time—it's not that it expects him to miss half a season in 2017, it's just that it's averaging the chance he is on the field with the chance he is not, and it lowers the number. If we want to look at the chances for Dunn's reaching the top 10, we need to give him more PA—consider this 3,498 and 192-homer performance the low end of the spectrum, and if you think that's off the mark or in either direction, realize that, from age 31 through his retirement, Ken Griffey Jr. hit 182 homers—low-end forecast, indeed.

PECOTA assumes Dunn will hit a homer every 18.2 plate appearances over the course of this nine-year period, so we can figure out how many homers he would be expected to pick up with more playing time. Kick him up to 4,000 plate appearances, and it comes out to 220 homers (219.6, but let's round up). Adding 220 to his assumed 355 gives him 575, which today would make him 11th all-time, but by the end of 2019 would more likely be 12th, thanks to Pujols. How likely is it that Dunn gets 4,000 PA before he retires, though? Only 182 other players have accumulated that many from their age-31 season on, with Pete Rose at the top end (9,649) and Jeromy Burnitz (4,011) at the bottom end.

Let's call that the most likely scenario for Dunn, as we already have a low end, and giving him more than 4,000 would be assuming everything goes perfectly for him (we'll get to that, but let's stick to realism for now). This is as unscientific as it comes, but a quick bit of crowd sourcing on Twitter (with the simple question: How many home runs will Adam Dunn finish his career with?) gives Dunn an average career total of 569.7, very close to the above estimate.

I said there were other problems outside of the PA, so here's the second one: Dunn is projected to hit just 62 homers combined in 2011 and 2012 (and if you count 2010's forecast for him as well, just 94 over three years). In Dunn's last three seasons (assuming the four more this year), he's averaged 39. Yes, he's coming off his peak, and will surely get worse before he becomes better, but if there's one thing you can set your watch by, it's Dunn showing off his homer muscle. He's closer to his 70th-percentile forecast this year than his weighted mean, so if we're to assume that we would be dealing with the same scenario for 2011 and 2012 (or an improved outlook due to 2010 success), then Dunn should be able to hit somewhere in the neighborhood of 70-80 homers in 2011 and 2012—the low end has him hitting 35 per year, the high, 40. That's more reasonable for a short-term forecast than the 62 combined, and, by adding the 8-18 additional homers to his 575, Dunn is set to finish with between 583 and 593, which would put him ahead of not just McGwire, but Robinson and Thome as well.

The plate appearance addition that bumped him to 4,000 is reasonable, so it all comes down to his performance in the next two seasons—how long can he stave off a drop in his power production? The longer he can do it, the better the chances that he ends up in the top 10, and also the better the chance that he continues to rack up plate appearances in meaningful sizes late into his career.

If Dunn is in the top 10 in homers in the twilight of his career, then 600 homers will be within reach. Would that be enough to vault Dunn, who is often undervalued for his contributions with the bat (but has lost so much value due to his glove in the outfield in the past) into Cooperstown? It's a question we're not quite ready to answer, given the hypothetical nature of the scenario, but Dunn does not carry the PED legacy of other sluggers who peaked before him—as a member of another era who is naturally enormous, he fits the mold of someone the BBWAA would be pleased to promote were he to put himself into the Hall of Fame discussion with the long ball.

One surefire way to earn that election would be to continue to rack up the plate appearances. If we add another 500 PA to Dunn's future (121 players have reached this mark from age-31 onward, with Robin Yount as the new bottom), using the same 18.2 PA/HR rate, Dunn is slated to hit 247 before we even account for the extra homers for 2011 and 2012. Don't laugh—Luis Gonzalez hit 247 homers from age-31 onward, Fred McGriff had 231, and 35 players had 220 or more total in this time frame. If we're talking about Dunn as one of the possibly 10-15 top homer hitters even in terms of counting, it makes sense to assume he could reach those heights.

Sticking with the 247 would give him 602 homers—add in the 8-10, and he finishes at least one ahead of Sosa. Considering PECOTA has no qualms about Dunn producing into a late age—the question has more to do with how often he is there to produce, as evidenced by a .285 TAv forecast at age 37—it's not difficult to envision a scenario where this happens, as long as he stays on the field. One other thing to remember is that Dunn is a free agent this winter—if he chooses to head to a hitter's park, or finally acquiesces with the wishes of the people and becomes a DH either now or on his next contract, there's a better chance of him hitting more homers, staying on the field, or both.

Let's open things up for discussion in the comments. Which of these three scenarios seems the most likely to you? What kind of numbers do you think Dunn will be putting up in 2011 and 2012, the seemingly key years for this entire process?

 Thanks to Rob McQuown for the data assist on age-31 and over players.