LeBron James' grounded game

— -- LeBron James did something Friday night we rarely see these days.

Late in the second quarter against the Toronto Raptors, Kyrie Irving attacked the basket, drew a double-team and flipped the ball to a cutting James, who slammed the ball home uncontested. If you watched the game, you may not have batted an eye over this sequence. A four-time MVP dunked. Big deal.

Actually, this season, it is a big deal.

Believe it or not, that slam in Toronto was just James' sixth dunk this season in the half court -- six. Reggie Jackson has more. So does Solomon Hill. Since James' highly anticipated return to Cleveland, he has registered 19 dunks overall, with 13 of the throwdowns coming in fast-break situations, according to NBA tracking. That leaves only six in traffic.

So if you've noticed that he hasn't made as many high-flying plays at the rim, your eyes aren't fooling you. Perhaps the NBA's most athletically gifted player of this generation has been strangely grounded this season.

On the surface, this seems so backward. James famously shed heaps of pounds this offseason as part of a strict sugar-free diet in order to make him lighter and more mobile. James told CNN's Rachel Nichols this offseason that the Cookie Monster haunted him in his sleep, but it's as if the  Sesame Street gobbler has been not just on James' mind, but his back, too.

One would assume James would have more lift, more bounce to his step this season. In fact, James has played below the rim more than ever. While the Cavs are on a roll, James is quietly on pace to have his worst season in years. The question is: Why? Let's dig in.

The numbers

Earlier this week, we revealed the real plus-minus (RPM) leaderboard on ESPN.com as we approach the quarter-mark on this 2014-15 season. As you may have guessed, some household names have taken residence in the top 10. Stephen Curry. Chris Paul. Tim Duncan. Anthony Davis. You know, the usual.

But you might have noticed a certain name not in the top 10: LeBron James, the overwhelming favorite for MVP this season. Judging by our sophisticated model, James' on-court impact has fallen off dramatically since last season. The latest update ranks James just outside the top 10, nestling in at 14th in RPM, which attempts to estimate his on-court impact on a per-100-possession basis after accounting for his teammates, opponents and additional factors.

Last season's RPM for James -- which included his postseason play -- was head and shoulders above the league at 9.08; Paul was second, with 7.98.

So, what gives? Well, we can't just write this off as a case of RPM "hating" on James. It isn't the only metric that has bumped James down the totem pole this season. Player efficiency rating (PER) ranks James ninth this season at 24.6. Pull up his career numbers and you'll find that he led the league in PER in eight of the past nine seasons (last season, he finished second). In fact, a 24.6 mark would be James' lowest since his 2006-07 season, when he checked in at 24.5.

As I hinted at the top, the bulk of the blame can be placed on James' struggles at the rim. Overall, James is shooting 47.5 percent from the floor, a far cry from his 56.7 percent mark last season. Driving that percentage down is the fact that James' otherworldly finishing abilities seemingly have disappeared this season. Last season, he was a freight train in the lane, shooting an NBA-best 72.9 percent on paint field goal attempts, according to NBA.com. This season? James' field goal percentage in the paint has fallen to 60.1 percent, which places him 37th, just behind the Sacramento Kings' Omri Casspi.

How the mighty have fallen. James just isn't dunking anymore in traffic. Sure, he unleashed a jaw-dropping double-pump reverse in the open court Tuesday night, but that's more the exception than the rule. James' dunk rate has never been lower over a full season. Right now, he's throwing it down 0.9 times every 36 minutes, which would be the first time in his career that it has fallen below the 1.0 mark.

James' dunks are not the only athleticism indicator on the decline. His frequency of and-ones has fallen as well. With less body mass to throw around, James has muscled his way to just 17 and-one opportunities this season, or 0.81 every 36 minutes -- his lowest rate since his sophomore season.

Want more? James also is posting his lowest rebound rate since his rookie season, pulling down just 8.6 percent of available rebounds, according to Basketball-Reference.com. His assists are up, but he has coughed up the ball a career-high 15 times per 100 plays. Until recently, he led the NBA in bad pass turnovers ( John Wall has 52 compared to James' 50, per NBAsavant.com). Is James just acclimating to new teammates? Or is this just a function of James nearing his 30th birthday? Or is it both?

The explanation

Dig around and you'll see James' numbers are way down this season. But it's harder to pin down exactly why this is occurring. It could be the case that James is just getting used to his new (or is it old?) surroundings in Cleveland. As we all know, the 2010-11 Miami Heat didn't get off to a great start, either. James had a big hand in that early struggle. Actually, James shot worse in his first 20 games in Miami (45.8 percent) than he has this season in Cleveland (47.5 percent). Check out the remarkably similar numbers through 20 games in 2010-11 compared to this season.

Crazy, huh? Almost identical. Many have pointed to his slimmer frame as the reason for his slow start. Shedding the bulk might very well have contributed to his fairly pedestrian shooting numbers in the paint so far. But the evidence suggests that, yes, while James hasn't been playing above the rim quite like he used to, it's also true that he has dealt with this sort of sluggish start in a new environment before, and was able to overcome it.

However, James was 25 then and he's about to enter his 30s later this month. Flipping that figurative switch won't be as easy this time around, especially after logging four straight Finals appearances on the odometer. That takes its toll. On the flip side, James' game is also much more refined now with a nifty post game and a sharper 3-point arsenal.

Riding an eight-game winning streak, the surging Cavs probably aren't desperate for signs of encouragement, but I'll offer this nugget anyway. After that rocky start in 2010-11, James shot just a shade under 53 percent the rest of that season, pulled down 8.1 rebounds per game and climbed back atop the PER leaderboard. In other words, he got back to being LeBron again, and the Heat eventually reached the Finals. This year's Cavs, I'm guessing, would take that in a heartbeat.