Fantasy Hockey: Chasing Plus/Minus Is A Fool’s Errand

Joe Pavelski
Joe Pavelski
Kyle Terada USA TODAY Sports

The thought occurred to me a few nights ago while discussing the upcoming season with a fellow writer that there are probably certain conditions that are necessary for a monster fantasy hockey season to occur. I’m not talking about Sidney Crosby putting up over 100 points or Alex Ovechkin scoring 50-60 goals. It’s the seasons that people didn’t see coming. Last year, I had Joe Pavelski as a top-70 forward in roto leagues; he finished third. I had Patrick Sharp as a top-35 forward; he finished sixth. In 2013, Alex Semin, Derek Stepan, and Mike Ribeiro all had top-20 roto seasons. While these guys are certainly not average hockey players, none of these five are among the elite in hockey.

So what, exactly, has to happen for guys to have an elite fantasy season? Here’s part 1 of the research: How big of a factor is plus/minus, and can it be predicted?

Fantasy Hockey Value of Plus/Minus

While this outdated statistic is completely irrelevant in studying the value of a hockey player, it nonetheless remains a staple of roto fantasy hockey leagues (for clarity: I assume ESPN standard roto leagues less Time On Ice).

In 2014, among top-10 fantasy forwards, Alex Ovechkin had by far the worst plus/minus of the group at minus-35. His top-10 standing was due to being elite at everything else except that and assists (thanks, teammates). Other than Ovechkin, Claude Giroux was the only skater in the top-10 that wasn’t at least a double-digit plus last year. Excluding the two outliers (Ovechkin at minus-35 and Corey Perry at plus-32), this is how much plus/minus accounted for an average top-10 skater’s value last year (13.67 average total value):

plus minus forward value

A few things about this:

  • These are all taken from ESPN’s Player Rater. While I would like to have different sources, the realm of fantasy hockey just is not that advanced yet. Using their Rater is probably the best way to approximate fantasy value. Issues can arise when translating this to other websites or league formats, but this is an exercise just to determine value and how to attain it, not which sites are best suited for fantasy sports.
  • Aside from the almost negligible value that penalties provide to elite players, plus/minus doesn’t have a ton of added value, either. In fact, averaging out the top-10 scores minus the outliers would give us an average value of 13.67 (or somewhere between Giroux and Pavelski). Of those 13.67 we’ll-call-them-roto-points, about 1.84 of them are from plus/minus, or 7.42-percent. That’s right, of an average value of 16.67-percent per category, only 7.42-percent of actual value is attributable to plus/minus.

What that chart also tells us is that seeking out plus/minus in an attempt to seek out the next big season is a bit of a fool’s errand. Sure, guys on teams like Edmonton, Calgary, Buffalo, and the like will have a hard time having a top-10 season because of the team they play on. With that said, I would estimate that for 75-percent of players, an elite plus/minus posting like Patrice Bergeron or Anze Kopitar should be near the bottom of the list of things to look for when looking for a breakout.

Factors Affecting Plus/Minus 

Now that it’s safe to say that evaluating plus/minus as a priority in player analysis for fantasy hockey is unnecessary, what exactly can lead to a good plus/minus? This is where analytics can be a good friend.

A good chunk of a player’s plus/minus is tied to his on-ice save percentage, or the rate at which shots are saved (at five-on-five) while a given player is on the ice. The NHL’s plus/minus leader last year was David Krejci at plus-38; his on-ice save percentage was .948. The NHL’s worse plus/minus last year (among forwards) belonged to Steve Ott at minus-38; his on-ice save percentage was .923.

Further to that, a good chunk of a player’s plus/minus is tied to his on-ice shooting percentage, or the rate that he and his line mates score when he is on the ice (again, at five-on-five). Krejci and his plus-38 enjoyed a 9.6-percent on-ice shooting percentage last year; Ott and his minus-38 enjoyed a 4.3-percent on-ice shooting percentage.

So it would make a lot of sense to study on-ice save percentage and on-ice shooting percentage if the goal is to estimate a future plus/minus, right? Not so fast.

On-ice shooting percentage tends to settle in a given range. Among the top-15 forwards last year, there are names like Crosby, Malkin, Benn, Kunitz, Perry, Getzlaf. Names like Getzlaf, Crosby, and Kunitz were also in the top-15 the season before (remember, that was just a 48-game season, so a lot of things hadn’t been able to work themselves out). Skilled players tend to have high, and consistent, on-ice shooting percentages, while lesser skilled players settle at a lower level (thanks to the Oilers blog Boys on the Bus for that one).

For on-ice save-percentage, not so much. The Philadelphia Flyers blog Broad Street Hockey found that the best guess for a forward’s on-ice save percentage the following season is league average (three season r-squared of 0.0033, or essentially negligible).

Not only is plus/minus not a significant part of an elite player’s value, but it’s partly at the mercy of his on-ice save percentage, and that’s difficult to predict. Maybe Krejci and Patrice Bergeron are decent bets to post a very good plus/minus again, but what about Marc-Edouard Vlasic, Ondrej Palat, and, Kyle Turris? All above plus-20 last year, but will it repeat? In short: maybe?

Those looking for a breakout player in a roto fantasy hockey league can effectively ignore plus/minus.

*Thanks to Extra Skater, Hockey Reference, Behind The Net, and ESPN for their resources.

author avatar
Michael Clifford
Michael Clifford was born and raised in Fredericton, New Brunswick, Canada and is a graduate of the Unviersity of New Brunswick. He writes about fantasy hockey and baseball for XNSports and FantasyTrade411.com. He can be reached on Twitter @SlimCliffy for any fantasy hockey questions. !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+'://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js,fjs);}}(document, 'script', 'twitter-wjs');