Ticats lucky number 13; assessing CFL win totals using Elo ratings

The Elo question for today: will the Tiger-Cats reach 13 wins?

I gave a simple explanation of CFL Elo Ratings and other ranking methods last week — It’s Elo not ELO.

You will find updated CFL Elo rating charts, odds and rankings at the end.

The predictive Elo ratings method we will use to answer the Ticats question applies to all CFL teams. As a result, we will assess the win total odds for all teams.

Elo ratings allows us to transform the relative Elo rating values of two teams into an expected win percentage.

The short explanation is that we will take the difference in the two Elo rating values, add a home field adjustment amount (65 points) and then convert into a percentage.

Equal odds of 50 percent are found when Elo ratings of the two teams are the same. At a differential of 100 the win expectation is about 65 percent, at 200 around 75 percent, and at 400 it is approximately 90 percent.

To determine an end of season win total for a team we take their current win total and step through the remaining games in the season. Each game we determine the odds the team wins against their opponent.

We end up branching the season at each game with X percentage odds the team wins the game (adding a win to their total) and 100-X percent odds they lose. After we evaluate the final game of the season, at the end of a branch, we can look back along its path to the start of the season and see what the accumulated odds were to reach that point. We then can add up all the probabilities across all branches, that result in the same win total to create the odds the team wins that total of games.

Below are two win total charts pre-Week 17 in the CFL. The first is produced using franchise Elo rating and the second via season Elo rating.

Hamilton has greater than 95 percent odds of reaching 13 wins. In fact, they are expected (have greater than 50 percent odds) to reach at least 14 wins.

We will see later that the Stampeders have the best franchise Elo Rating in the West. This lead is even closer in season Elo rating. Despite this advantage, the Stampeders have roughly the same odds as the Riders to reach 10-14 wins by franchise Elo and have worse odds in season Elo. This is due to their much greater strength of schedule (Montreal on the road, Saskatchewan at home, Winnipeg in a home-and-home, B.C. on the road).

What are the ‘stories’ from the CFL franchise Elo rating charts?

Calgary on a bye watches Winnipeg stumble and Hamilton take their place.

Saskatchewan and Edmonton win games they should versus Toronto and Ottawa.

B.C. continues to show they aren’t as bad as Ottawa and Toronto late in season, but have only done it against a Montreal team without Vernon Adams Jr. and prior to that versus Ottawa in a home-and-home.

What is different in CFL season Elo rating charts?

Hamilton is on top, knocking Winnipeg down into the big West fight between Calgary, Saskatchewan and Winnipeg.

The East Semi-Final matchup of Montreal and Edmonton has a chance to be a competitive game depending on how Edmonton plays moving forward without Trevor Harris.

Divisional finishes

The crossover expectation is currently at 99.9 percent.

The continued expectation is that the participants in the playoffs will not include B.C. in the West, nor Ottawa or Toronto in the East. The total between those three of any of them making the playoffs is a measly 0.3 percent. B.C.’s odds are 0.7 percent.

We know Calgary, Saskatchewan, Winnipeg and Hamilton are in the playoffs.

B.C. has a one game margin to make playoffs, they need Edmonton to lose all their games and to win all of their own. If one game doesn’t go B.C.’s way, an Edmonton win or a loss of their own, then their playoffs hopes are done.

Toronto and Ottawa can technically still catch a playoff spot. Each of them essentially need Edmonton to not win any games and to win all of theirs. Then they could take the tie break and stop the crossover. They can also attempt to catch Montreal by winning all their games and hoping to take the tie-breaker with their remaining regular season game versus Montreal. Both teams essentially have a one game margin on each of these scenarios, an Edmonton and Montreal win or a loss of their own makes this an unreachable goal.

Hamilton is almost guaranteed to be first in the East (99.9 percent) and host the East Final after a bye.

As was said last week, Montreal should be preparing to host Edmonton in the East Semi-Final (99.9 percent) as they crossover from the West (99 percent).

Playoffs odds

Hamilton is the favourite to make the Grey Cup (78 percent). This is an accumulation of factors such as having the bye and then playing the weaker two of the other five playoff teams.

Things are still close out West. Saskatchewan has slipped past Winnipeg. If you consider season Elo rating and an easier strength of schedule, then they might have an inside chance at first in the West.

Grey Cup matchups

Hamilton features heavily given how expected it is that they would make it out of the East over Montreal or Edmonton.

Hamilton is in the Grey Cup in 78 percent of the matchups with the most likely competitors being Calgary, Saskatchewan or Winnipeg based on their current standings expectations.

A Grey Cup featuring only West division teams is at nine percent odds.

Strength of schedule

Winnipeg still maintains the hardest strength of schedule. Of playoff teams, Hamilton has the easiest, followed by Montreal. Calgary, Edmonton and Saskatchewan have roughly the same future schedule.


One thing that stands out in this week’s rankings is Saskatchewan’s Markov Chain ranking. Season Elo rating and RPI, which are based more on winning rather than score, have the Riders ranked stronger than Markov Chain. The Markov Chain method is all about points for and against opponents. The implication is that the Riders win, but the margin of victory has not been convincing relative to their opponents in those games.

The implied tiers of the average of the season ranking methods are:

1. Hamilton

2. Calgary and Winnipeg

3. Saskatchewan and Montreal

4. Edmonton

5. B.C.

6. Toronto

6. Ottawa

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