Projecting the last month and a half of the regular season

As of August 13 the Cubs have 44 games remaining on their schedule and the standings in the NL Central look like this:

It doesn’t get much tighter than that. So I spent some time on Monday’s off day comparing what the different projection systems had to say about the race in the Central. You can read a bit about three different projections and how they got their numbers below.

Fangraphs

Fangraphs generates their playoff odds by running 10,000 simulations of the regular season with the current data. You can read more about that method below:

To generate the playoff odds, we take the current standings, the remaining schedule, the team’s projected performance, and we simulate the remaining season 10,000 times. All the outcomes are averaged to find the probably of wining the division or wild card along with winning the World Series and various playoff rounds. If a team has a 90% chance to make the playoffs, that means that 9,000 out of the 10,000 simulated seasons end in the team making the playoffs.

We also report a projected W and L record. This is the average of the total wins in each of the simulated seasons for the team.

A value of 100.0% does NOT mean a team has clinched. It only means that a team made the playoffs in at 10,000 seasons (9,995 with rounding) of the simulated 10,000.

So, what does a run of 10,000 seasons at Fangraphs predict for the NL Central? See for yourself below:

Fangraphs

As you can see this projection has the Cubs going 24-20 or 25-19 over their last 44 games and winning the division by four or five games. I’m not going to lie, that would be a nice, comfortable finish after last year’s down to the wire disappointment.

The Fangraphs metric also gives the Cubs an 86 percent chance of making the playoffs and believes it’s more likely the Cubs will win the division than play in the Wild Card Game, which would also be a relief after the way 2018 ended.

Baseball Prospectus

PECOTA’s algorithm really doesn’t like the Cubs. This algorithm had the team projected at 79-83 to start the year and depending on the day had them dead last in the division. After the Cubs acquired Craig Kimbrel PECOTA bumped them to an 81-81 team fighting for third place in the division. It’s worth noting that with an extended run of sub-optimal play both of those outcomes are possible, albeit not likely. The Cubs would need to go 15-29 or 17-27 down the stretch to finish at PECOTA’s original projections. It would be their worst extended streak of baseball in the last five years if it happened. It’s also worth noting that even PECOTA no longer thinks these outcomes are likely. Below are the most recent rest of season projections from Baseball Prospectus:

Baseball Prospectus

PECOTA’s system is different than Fangraph’s because rather than simulate games at a team level it takes player level data and tries to project results. As you may have surmised, it’s not particularly bullish on the Cubs players. That said, PECOTA seems to finally have reconciled itself with the fact that the Cubs are not a .500 or a sub-.500 team. This projection would have the Cubs at 87-75 at the end of the year, one game ahead of the 86-76 Cardinals.

FiveThirtyEight

FiveThirtyEight runs a simulation method similar to Fangraphs however their underlying data is slightly different. They use an Elo method that is based on how chess rankings are determined. First, lets look at what Elo entails:

What’s Elo, you ask? Named after the Hungarian-American chess master (and power-ratings pioneer) Arpad Elo, Elo is a simple way to rate competitors that can be tuned and customized endlessly to incorporate available data. For our purposes, each MLB team carries a rating that estimates its current skill level. (The average is about 1500.) After every game is played, the winning team gains some rating points while the losing team loses the same number of points, based on the chances our model gave each team to win the game beforehand (and the margin of victory). For example, a win by a big underdog results in a bigger exchange of points than a win by a favorite — and the larger the margin of victory, the larger the exchange.

They take those game by game predictions and run a “hot” model of thousands of simulations:

Now it’s time to turn these team and player ratings into probabilities, tracking how often each team makes the playoffs or wins the World Series. To do this, we run Monte Carlo simulations, playing out the season thousands of times. As with our other sports forecasts, we run these simulations “hot,” meaning that a team’s rating doesn’t stay static — rather, it changes within each simulated season based on the results of every simulated game, including the bonus for playoff wins. Starting with the 2019 season, our team ratings change at three-quarters of the speed they previously changed. As a result, the “hot” simulations have a bit less variance, and the forecast’s overall uncertainty is decreased a touch.

These simulated games also account for starting pitching matchups; for games in which a starter is not yet known, we assume that the most-rested pitcher from the team’s regular rotation will play. During the postseason, we assume teams use a four-man rotation.

So, what does FiveThirtyEight think of the Cubs chances as of today?

FiveThirtyEight

A few notes — first of all, there was no way to fit all of the teams in a single readable screenshot. This shot gives you every team with a greater than one percent chance of making the playoffs except the Giants. My sincere apologies to the three percent chance Giants. Second, by Elo score the Cubs are the third strongest team in the National League behind the Dodgers and Nationals, but the Braves, Mets, Cardinals, Diamondbacks and Brewers are all close behind.

Finally, despite slightly different inputs we can see that the FiveThirtyEight model basically agrees with the Fangraphs model that the Cubs are likely to wind up somewhere around 24-20 through their last 44 games for an 88-win season and first place in the N.L. Central.

Takeaways

The division is as tight as it’s been in years and all of the people who run these models would tell you that projections are not promises. The Cubs find themselves in a slightly better position than the other teams in the N.L. Central, but a bad run of baseball could shift these odds pretty quickly. Winning their series against the Phillies and Pirates would go a long way to improving their odds in what looks like a Division race that could come down to the wire.

*Full disclosure, the author also writes for Baseball Prospectus’ Short Relief.