To say the Cleveland Cavaliers and Toronto Raptors have taken different paths to the NBA Eastern Conference Finals would be quite the understatement. The Cavs easily swept their first two series, against the Pistons and Hawks; the Raptors were pushed to seven games in each of theirs, with the Pacers and Heat. Toronto played its last game this past Sunday; Cleveland last played the Sunday before that. As a result, LeBron & Co. have an enormous advantage in the rest department heading into Game 1 at home Tuesday night. But will it help the Cavs much? Don’t bank on it.
The Cavs already enter the series as heavy favorites: Our Elo-based forecast gives them a 74 percent chance of prevailing. And the seven-day rest differential over the Raptors is tied for second among the 230 playoff series occurring in the second round or later since 1984, when the league launched the 16-team playoff format. (The largest difference in time off was nine days, in the 2004 Pacers-Heat series.)
Such a long layoff for one team and a tight turnaround for the other can spin either way — rest or rust — but there isn’t any statistical evidence that inequalities in rest between series help or harm teams in the playoffs.
We looked at this a couple of ways. First, if either rust or exhaustion is going to have an effect, it’s most likely to come in Game 1 of a new series. Using both teams’ pre-series Elo ratings (FiveThirtyEight’s pet method of estimating a team’s strength at a given moment), we can calculate expected point differentials for those opening games and then compare them to the games’ actual scoring margins. Teams that got more days off than their opponent did not do better than expected in these Game 1s, in terms of their expected point margins; any benefit of extra rest wasn’t statistically significant.
But that’s just looking at Game 1s. What about the whole series? As a second pass at the question, we used a logistic regression — a nifty statistical tool for examining outcomes such as wins and losses — to test whether the difference in rest days between the two teams had any impact on the series outcome, after accounting for the series’ Elo-based forecast. The series projection had major significance in predicting who went on to win — no surprise there. But the differential between teams in rest days was not a statistically significant factor, just as in our analysis of Game 1s.
But smoking out relationships between rest and rust and the outcome of a series overlooks the most important factor: the quality of the teams. A breakdown of the average differential in Elo between the two teams, sorted by difference in the number of days off between series, shows that better teams are more likely to close out their series quickly, and worse teams that do win are more likely to do so in a longer series.
For the Cavs-Raptors series, what really matters is not Cleveland’s long vacation nor Toronto’s heavy workload, but the simple fact that the Cavs are the better team. Rest was never going to change that.
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