Nylon Calculus: Which players would be the costliest injuries?
Injuries are an unfortunate reality in any professional sport — foremost as a painful risk to players, but they also deprive fans of great performances and teams of production. The NBA is only a couple of games into their shortened preseason and already there have been significant on court injuries to Dante Exum, Nicholas Batum and Markief Morris.
Injury risk and recovery is a large subject of research that is woefully under-explored in basketball and sports generally. In part, it’s due to the mostly valid excuse of a lack of good public data, plus the complexity of medical issues and diagnosis.
When I do my preseason NBA win projections, the best I have been able to do is to hedge my bets as to which players are likely to lose significant playing time. The starting premise is that relatively few players appear in all 82 games. In the last three years an average of 21 players per year have appeared in all 82, per Basketball-Reference — a list, I would note, that includes currently injured players like Isaiah Thomas, Morris and Exum.
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While there is a correlation from one year to the next in games missed, it is not particularly strong. Generally, the estimate used is that an NBA player will miss one game for every six he missed the prior season until you get to 76 games. So a player that missed 24 games the prior year, appearing in 58 games, is projected to play in 72 games the next year.
What if scenarios
Given the difficulty in accurately predicting injury risks prior to the season, I decided to try another way to look at injury risk — which players are the most vital to their team’s ability to win games?
By using the depth charts I developed for my win projections I estimated the players whose absence would be the biggest blow to their team’s win totals. This method has the advantage of having relevance for trades and other scenarios in addition to injuries
The simplest way to look at this is the gap between the starter and his backups, the larger the gap the more the team will suffer the loss. The depth chart estimates and these impact estimates rely on the five cardinal positions as a proxy for quality of the player’s replacements. This is only a rough approximation. But when searching 150 projected starters in the league, it’s a good enough starting point.
I first chose to scale the loss as a percentage of the team’s’ expected wins. This is a way, in part, to prevent the entire list from being Golden State Warriors. (They’re pretty good, in case you didn’t know.) But there is enough talent on the team that losing three or four more games probably still leaves them in command of the league’s best record in most scenarios.
The estimates below have the top-10 players by projected net impact on the team’s win percentage compared to their backup. All are estimated as if the player is out for half the season.
Near the top of the list is LeBron James, which is a decent smell test validation. To be fair, part of the net impact comes from the rating for his backups at small forward such as the venerable Richard Jefferson. If we slide Jae Crowder down from the four the impact is a little less. But it should be said that Crowder as a 3-and-D wing doesn’t attempt fill the same role as LeBron, no matter what position we call him.
George Hill makes the list based on three factors, 10 percent of Sacramento’s expected wins is not a big number. And his rookie point guard backups don’t figure to be productive in their first year. He’s also pretty clearly the King’s best player.
Mike Conley is good. His potential backups are not. It’s hard to see how this Grizzlies team would weather a major absence by either Marc Gasol or Conley, unless it’s simply the uniforms that allow them to outperform their pythagorean wins every year.
Tim Hardaway Jr is a bit of a surprise entry, but in addition to scoring better than most places in my projections, Hardaway gets the benefit of the same factors as Hill. He is playing on a team with a small base of talent and his backup is not good.
The simple projection here probably doesn’t capture how much of an actual loss a Giannis Antetokounmpo absence for half a season would represent to the Bucks. But, put plainly, it wouldn’t be great. There isn’t that much NBA talent behind him at the small forward, save Jabari Parker, who is already out for half the year.
The $23 million man in Philly, J.J. Redick, is the next hig- impact loss on the list. That’s a good thing, as he’s making $23 million. It’s yet another case where the lack of a competent backup increases the effect considerably.
The next two entrants on the list, Evan Fournier and Kentavious Caldwell Pope, along with a Allen Crabbe a few spots further down are the worst three starters on the list according to my projections. They are also all, not coincidentally I’d argue, shooting guards. Shooting guard is perhaps the least deep position in the NBA, and it shows in the effect of the loss of even a competent starter at that spot.
On the other end of the depth perspective, Myles Turner is the only center on this list. Most teams have at least a passable back up, even impact centers like Rudy Gobert and Nikola Jokic don’t show up here. Turner’s backups Lavoy Allen and Al Jefferson don’t project as quite that level,
Eric Bledsoe hits the same, “Only plus player on the entire damn team,” mark that Hill hits. Him being out for half the year projects to “cost” Phoenix half their wins. Expect the Suns front office to begin sitting Bledsoe in November.
Honorable mention for Hassan Whiteside, who almost made the list. If the Heat couldn’t slide Kelly Olynyk over to center, Whiteside makes the list as the win loss falls from seven percent of expected to four percent. To be honest, if Whiteside goes down, the Heat should and will probably just slide Olynyk in at center.
A second honorable mention goes to Anthony Davis, who just misses the top-10 list and is the power forward whose absence would be the biggest impact on his team’s win total, taking six percent of the Pelican’s expected wins.
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The most systematic takeaway is the relative lack of depth on the wings and at the point compared to the big positions. In terms of potential playoff teams, the Cavaliers, Grizzlies, Pelicans and Bucks appear to be the most vulnerable to the loss of a key player. Some of the other players are simply the best player on talent hungry teams, but worth watching for the race for lottery balls.