This week's mailbag takes on a single question -- one that has been asked about a number of superstars.

"Watching the Cleveland Cavaliers play has had me rethinking the media's constant statement that LeBron James makes his teammates better. Has anyone ever actually gotten better once they went to the Cavs/Heat? Off the top of my head, everyone on their current roster was better on their previous teams, besides maybe J.R. Smith."

-- Patrick Stock

Let's start by talking about what it means for a player to make his teammates better, and what it doesn't mean. With the exception of the occasional situation in which a player is inspired to improve his game by the example of a star teammate, we don't actually mean that the teammates become better players. What we mean is they perform better because of the playmaking provided by or defensive attention drawn by a star.

If a value metric is well-calibrated, that uptick in performance should be credited to the star player through his assist and usage rates. So ideally, we'd never show a player making his teammates better statistically, as any improvement in their efficiency would be offset by a decline in their usage rates and an uptick in assisted field goals.

That being said, what do we actually see with newcomers to the Cavaliers? I'm going to compare their performance to what my SCHOENE projection system forecast entering the year. While that's not always a perfect capture of how good midseason acquisitions were on their previous teams -- George Hill, for example, was underperforming his projection with the Sacramento Kings before being traded to Cleveland -- it should be a useful point of comparison on average. And the results aren't pretty.

I'm also including holdover players from Cleveland's 2014-15 team, who were new to playing with LeBron, and using a minimum of 400 minutes played for the Cavaliers in their first season. Of the 25 player-seasons that meet my criteria, just nine of them have matched or beaten their projected player win percentage (the per-minute version of my wins above replacement player metric).

Performance of new LeBron teammates Player Season Projection Actual Ratio Channing Frye 2015-16 .427 .552 1.29 Larry Nance Jr. 2017-18 .500 .636 1.27 Timofey Mozgov 2014-15 .439 .530 1.21 Jeff Green 2017-18 .365 .432 1.19 Tristan Thompson 2014-15 .440 .478 1.08 Jose Calderon 2017-18 .385 .410 1.07 JR Smith 2014-15 .510 .543 1.06 Kyle Korver 2016-17 .476 .492 1.03 Richard Jefferson 2015-16 .387 .387 1.00 Iman Shumpert 2014-15 .462 .452 .98 Anderson Varejao 2014-15 .520 .499 .96 Dwyane Wade 2017-18 .488 .466 .95 Rodney Hood 2017-18 .422 .402 .95 Kyrie Irving 2014-15 .648 .599 .92 Mo Williams 2015-16 .434 .387 .89 Kevin Love 2014-15 .700 .599 .86 George Hill 2017-18 .507 .432 .85 Matthew Dellavedova 2014-15 .437 .371 .85 Shawn Marion 2014-15 .462 .380 .82 Dion Waiters 2014-15 .439 .351 .80 Deron Williams 2016-17 .473 .372 .79 Mike Miller 2014-15 .438 .335 .77 Jae Crowder 2017-18 .532 .391 .74 DeAndre Liggins 2016-17 .464 .341 .73 Isaiah Thomas 2017-18 .632 .389 .62

There actually are several members of the current Cavaliers roster who have been better than they were in previous stops. Jose Calderon and Jeff Green have performed well on minimum-salary contracts this season, Larry Nance Jr. played at the highest level of his career after coming over from the L.A. Lakers, both Smith and Kyle Korver improved after midseason trades, and Tristan Thompson developed into a key player after James signed in Cleveland.

Despite those examples, on average these new James teammates -- weighted by minutes played -- have performed 6.3 percent worse than forecast. Let's take a closer look at their component statistics in terms of the ratio of their actual and projected performance.

• 2-point percentage: 1.021

• 3-point percentage: .978

• Offensive rebounding percentage: 1.079

• Defensive rebounding percentage: .967

• Assist percentage: .805

• Steal percentage: .890

• Block percentage: 1.183

• Usage: .937

• 3-point attempt percentage: 1.070

• FT attempt percentage: .946

• Turnover percentage: 1.011

New LeBron teammates have in fact shot slightly more accurately on 2s, but surprisingly have done worse than forecast on 3s. The improvement in efficiency hasn't been enough to make up for a sizeable drop in usage (6.3 percent lower than forecast) and an even bigger one in terms of assist rate (19.5 percent lower).

By itself, it's tough to interpret this result, so let's take a look at the performances of players joining other teams with high-usage creators over the same timeframe. As comparisons, I used the Golden State Warriors, Houston Rockets and Oklahoma City Thunder. Of those teams, only newcomers to the Warriors beat their SCHOENE projections on average, though Cleveland has seen a larger decline than the other three.

Newcomer performance comparison Team Ratio Warriors 1.058 Rockets .978 Thunder .952 Cavaliers .937

Drilling down on Oklahoma City, there are really two different eras. During 2014-15 and 2015-16, with Kevin Durant on the roster, new players performed close to their projections (.987 ratio). Since Durant's departure, that has dropped to .938 -- almost identical to what we've seen with new LeBron teammates for the Cavaliers.

Patrick also asked about LeBron's Heat teammates, and looking at them is interesting because their ratio of actual performance to projections is almost exactly 1 to 1 -- .997, to be precise. Usage rate provides an interesting clue as to the difference between the two situations.

Despite including Chris Bosh and Dwyane Wade, who had monstrous usage rates the season before the Big Three formed as the lone All-Star on their teams, the weighted average for projected usage for new James teammates in Miami was just 17.4 percent -- far lower than league average (20 percent). By contrast, new LeBron teammates in Cleveland have a projected usage rate (again weighted by minutes played) of 19.4 percent.

If we look at the new James teammates who have beaten expectations in Cleveland, it's almost exclusively players with low usage rates. Just one of the nine to match or beat their projections (Smith) was forecast for above-average usage, and their average projected usage rate was 15.8 percent.

To some extent, this is a natural outcome. Part of the metric calibration I mentioned above is valuing the tradeoff between usage and efficiency. This relies on measuring the average extent to which players get less efficient in smaller roles, but each individual has a different degree of sensitivity to how much they're being asked to do on offense. Star players are valuable precisely because they see less drop-off than role players in smaller roles. At the same time, they benefit less in terms of efficiency from playing alongside a high-usage teammate like LeBron.

Still, these results seem to offer an important takeaway for any team that signs James this summer (including the Cavaliers). While some additional shot creators are necessary, particularly in a playoff setting, any team with James must be careful not to invest too many resources on players who are best with the ball in their hands. Instead, the focus should be on finding role players whose games will mesh well with LeBron's.