MLR is starting up again, which means its another round of changing teams. This year we have lost three teams and gained three, keeping the total at 12. Rugby ATL was sold, and new ownership has moved the team to Los Angeles. With the move comes a rebrand, which is about as bad as the last one was, but also changes up the squad enough to basically be a new team. Both New York and Toronto have folded, and been replaced by one planned expansion - the Miami Sharks - and one surprise team, Anthem, in North Carolina - a development oriented squad that is a joint effort of World Rugby and USA Rugby. This leaves us with just 9 teams we have some historical performance for, and 3 that we need to start making predictions for.
Usually, a new team is given a predefined mean rating and a very high variance, with that variance decreasing over time as the team plays some matches. Those matches won’t have much of an impact on the new teams’ opponents, because of the high variances, and we should arrive at a decent rating for the new teams within just a few matches. But we have the opportunity to come up with a more intelligent bayesian prior - essentially just a best current guess - at the new team’s ratings if we look at the squads that have been announced.
These are the rankings for the nine returning clubs:
We have the two finalists at the top, and roughly match the 2023 table with the current club rankings. So this all seems sane, and will be our comparison point going forward.
We can take the released squad lists and our player rankings to pick the “best possible” lineups for each of these clubs, and then generate some possible performances for them. That results in this plot, which has a very messy x-axis unit we can mostly ignore and just talk about order and overlap instead:
We again have the semifinalists at the top, but the Hounds are much higher than in the club model and the Jackals are not quite at the bottom. This may point to the importance of some measure of familiarity between players - teams that have been around and stable for longer perform better than you’d expect looking at just the players, and new teams perform a bit worse than you’d expect looking at the players. From just the lineups, we have three groups of teams - a close top 4, a lagging bottom four, and then the four in the middle. All the expansion teams are towards the middle - LA at 6, Miami at 8, and Anthem a bit worse at 9. But as we saw with the Jackals and Hounds, new teams may need to have slightly lower club scores.
So now we get to make guesses. We have RFC LA as the strongest of the expansion clubs, and Anthem as the weakest. Anthem looks to be about as strong as the Jackals - our lowest rated club. LA is about as strong as Houston and Utah, while Miami is more like Utah, NOLA, and DC. We can definitely start all three with very high variances, though could argue LA should have lower variance and Anthem higher variance.
That gives us a pre-season ranking like this, which seems to make more sense to me
