By: Patrick W. Zimmerman

“Just wait ‘til next year!”

—Seemingly every baseball fan ever

It’s a month out from opening day (March 28^th), and the really big fish on the market have finally overcome market forces (::cough:: collusion ::cough::) to find homes in San Diego and Philly. So we were wondering, which teams fans have already gone off the deep end? 

Hope springs eternal every spring, supposedly.  Is that actually true? Are fans really that irrationally optimistic?  Or, conversely, are fans fickle and impossible to please?

Let’s find out!  Which teams’ fans twitter fanbases seems the most optimistic? Most pessimistic?  And do the computer models suggest they have any idea what they’re talking about?

It’s ranking time.

The question

How does the mood of every team’s fanbase on Twitter compare to its predicted performance in 2019 per the computer models?  That is to say, which teams fanbases are over- or underrating their teams?

The short-short version

In general, if you want positive fans, apparently you should run a team that isn’t any good in a relatively small market.  If you want grumpy fans, consistently win ballgames. 

That sounds harsh because it is. 

The methodology

To gauge fanbase mood, we scraped hashtags across Twitter for every team on February 28^th, after both Harper and Machado had signed and exactly 1 month out from opening day.  To avoid potential confounds, we picked the obvious ones like [spanformula]#pittsburghpirates[/span] rather than broader things like team names that could be referring to other things like [spanformula]pirates[/span]. We then subjected the 15,000 tweet corpus to a sentiment analysis (tweaked for baseball terminology, where [spanformula]hit[/span] is a positive statement) through the University of Málaga’s Lingmotif text analysis tool.

For our computer models, we just took the average of Dan Symborski’s ZiPS model and Nate Silver / Baseball Prospectus’ PECOTA.

For each metric, we took at the z-score as a measure of its measure relative to the rest of the league, then simply subtracted the model z-score from the optimism z-score to arrive at our expectation index.

The results

Who’s most ready for the 2019 season, and who fears for the fate of all mankind?

Important Note: Z-scores will show positive and negative ratings relative to the league as a whole, so a team like, say, Pittsburgh, can have a below-average fan sentiment score (-0.03) while simultaneously having a fanbase that is feeling, in general, positive about the upcoming season. Indeed, there is only one team with a net negative sentiment score: Giants Twitter is a dark, dark place right now.

The sweet spot for optimism seems to be relatively good (but not dominating) teams in small markets.  Oakland, Milwaukee, and Colorado all show up, along with the back-in-the playoffs Atlanta Braves.  Plus the Padres, who have some justification, having just signed Manny Machado for the low, low, price of 94% of Balboa Park. Each of these teams has a fanbase that seems to have convinced itself that its team is on the way up and that (gasp!) even a future dynasty could await. 

The pessimistic end of the spectrum is a lot weirder. Sure, Giants and Tigers and Marlins fans are in the dumps because, yeah, their teams are going to suck.  Houston, Cleveland?  What is going on with you, 2^nd and 3^rd ranked teams not long separated from a World Series appearance?

Ok, enough fanbase wonkery. What do the fancy spreadsheets say?

Measuring fan expectations

Putting this all together, we present the Relative Optimism Index.

The sweet spot to have upbeat fans relative to expectations seems to be mediocre or bad teams in small markets.  Of our top 5 most positive fanbases, only Oakland is predicted to play .500 baseball, and them barely (by ZiPS, not PECOTA).  Baltimore?  Sure, they’re almost certain to improve on last season’s 115-loss season, but a massive improvement, according to the models, is a 13 win gain all the way up to 102 losses. 

At the other end of the spectrum, the lesson seems to be “good teams will have whiny fans.” Of the 15 teams underwater in the Relative Optimism Index, exactly two of them are project to have below .500 records (Arizona, projected for an 80-84 record, and San Francisco, looking at a 74-88 record).

Putting it all togther, we have a measure of how much a given fanbase over- or under-rates its team’s chances.

The only advice that we can offer here is, then, this: People, relax and enjoy your good baseball while it lasts. Because you’re not all Red Sox, Yankees, and Dodgers fans who can expect their teams to spend enough to guarantee at least a decent squad every year.