Over/Under Win Totals 2019: Fade Those not Trying

It's time to look at the 2019 MLB season from a wagering perspective. I'm a big fan of the season win total bets ever since I started making them in person in Las Vegas in the late 1990s.

It's a good exercise before the start of each season not only to make predictions on where you think the teams will finish, but also test those against the conventional wisdom expressed through money wagered in sportsbooks.

Over the last 18 years, I've come out ahead. My overall record is 47 for 82 (with one push) for 57.3 percent. My best bet each season is 16-13 (I had multiple biggest bets some years). I'm a little better on bets of $100 or more (I vary my bet size to emphasize how strongly I feel about the pick) where I'm 13-9 (59.1 percent). I'm most impressive on a weighted or cash basis, where I've been correct 61.5 percent of the time ($3,075 in winning bets, $1,925 in losers - not factoring in the vig).

I finally had a good season last year after a recent slump (1-7 the past two years), winning all three of my bets. (under on Arizona, Detroit and San Diego).

When I started writing this story in 2000 my idea was to see if you could be successful on these bets by sticking to some basic principals similar to investing in the stock market. While all kinds of new data has emerged and the stock market has seen some changes, the basic principles of Value Investing still work. Similarly, could we take basic sabrmetrical principles and apply them to the market and consistently win? As a result I've hesitated to add new metrics by diving into batted-ball data, Statcast metrics and WAR calculations. A few losing years had me questioning if the times have caught up with me, so it was good to have a bounceback season.

Back in 2000, finding the lines for these bets wasn't a trivial exercise. They were rarely online and few sportsbooks in Las Vegas posted season win totals (I had to trek to the dank sportsbook at the Imperial Palace). Today we're in a new world with the overturning of PASPA and every state free to legalize sports betting. My guess is that we'll see a lot more variations of ways to bet season win totals such as cashing out during the season and maybe someday taking the other side of the bet. We'll have to see if my methods hold up for the new offerings.

There's certainly a lot more media coverage of the win total lines as back in 2000 I was one of the few writing about them. Among the other great reads on the subject his year are Jonah Keri at TheAthletic, Aaron Gleeman at Baseball Prospectus and Joe Sheehan at his newsletter.

Here's my take on each team with more analysis below on those I selected as my "bets."

For this exercise, I'm using Odds from FanDuel Sportsbook which I grabbed on March 20.

When I look at a upcoming baseball season, there are eight methods I use to judge which teams might be a good bet: Three are statistical, four are observations I've had watching the bookies set season-long lines for MLB and other sports and lately I've thrown in a wild card pick with no particular theoretical basis. Here's the breakdown on these theories and the teams I decided to actually wager on.

The Johnson Effect

The Johnson Effect argues that a team that scores more runs or allows fewer runs than most statistical formulas would suggest, is bound to regress the next season. For example, if one team scores more runs than sabrmetrical formulas such as Runs Created or OPS might suggest, then it will score less the next season. The theory works based on the fact that sometimes a team has more success than it should just based on pure luck. A bad bounce here, a fluke play here - they can add up in one season and make a team look more powerful than it should be.

My favorite type of statistic for this analysis is a tool called the Pythagorean Theory. You probably learned the Pythagorean theory in trigonometry, but in baseball it means that the ratio of a team's wins and losses will be similar to the relationship between the square of its runs scored and the square of its runs allowed. If the runs a team scores and gives up in any given season don't translate into the expected win total from the Pythagorean Theory, that means something odd took place that should turn around next season.

Using the Johnson Effect and applying the Pythagorean Theory, who looks like they'll rebound in 2019? Here are the top teams that should have seen more or less wins based on their 2018 runs allowed/created than they actually tallied:

I usually like to look for teams that have a differential of 10 or more games. The Mariners are an easy target to decline since they've decided to rebuild, trading away Robinson Cano, Edwin Diaz, Jean Segura, James Paxton. The fact that they likely overachieved last season based on their Pythagorean number adds to their diminished outlook. Unfortunately the sportsbooks also agree as they're seen declining by 16.5 wins. I don't see a lot of value as a result.The Dodgers won 92 games last year, but were seen underperforming by this metric. They've averaged 94 wins the past six seasons, but have only finished above their 2019 over/under total of 93.5 just twice (102 wins in 2017, 94 in 2014). I don't see a great value with the Dodgers either.

The Plexiglas Principle

This theory says that any team that improves dramatically in one season is likely to decline the next season.

What teams made such dramatic moves from 2017 to 2018?

Since 1970, teams that have improved by 19 or more games declined by 7.2 wins the following season. The decline is even sharper for teams that have improved by 22 or more games (-10.68 games). Unfortunately the sportsbooks agree and have the A's declinning by 13.5 games in 2019. That drop may be too far, but I think the risk is too much to the downside with their thin starting pitching staff despite some young hitters who could improve dramatically. Atlanta could also take a step back before it becomes a regular contender after last year's breakout season. However, they feature a young core and have a pletheora of young arms and could even improve despite a tough division. I don't see a lot of value either way in a projected -4.5 decline.

The Reverse Plexiglas Principle

When a team has consistently been a winner and then experiences a sudden drop off, there is a strong likelihood that its win total will rebound. Or at least that's my theory. I haven't had a lot of success with this bet (1 for 4).

Here are the teams that declined the most in 2018:

The Nationals, Indians and Dodgers are the three teams that fit the mold. The Dodgers we can write off a bit just because they won 104 games in 2017 and some regression may have been expected. The Indians didn't add much in the offseason, so they seem a candidate to decline more than improve.

The Nationals seem the best fit. Yes, they lost Bryce Harper to the Phillies. But they added veterans in Brian Dozier, Patrick Corbin, Trevor Rosenthal and Yan Gomes, feature some of the best young hitters in the game in Juan Soto and Victor Robles, and still employ arguable the best pitcher in the game in Matt Scherzer. Before last year's vexing decline, the Nationals had won 95 or more games three of the last four seasons. The Sportsbooks only have them improving 6.5 games. I think they're a good bet to win 90+ games again. I'll bet $25 the Nationals win more than 88.5 games.

The last thing I look at is what teams the bookies think will have the biggest improvement or decline.

The Bottom Feeder Bet

This is totally from a non-scientific study of watching the bookies set the lines on expected wins over the years. People tend to care less about the bad teams in any sport, so the line is set a bit lower to entice folks to bet on these doormats. I've won 6 of 9 bets since 2001 with this theory. Let's look at this year's candidates.

The Orioles won just 47 game last season, finishing a record 61games out of first place. The Buck Showalter (manager) and Dan Duquette (GM) era ended with new management put in place in the offseason. Not much help is on the way as Baltimore's farm system is ranked last in the majors by ESPN's Keith Law. It's no surprise that they're the lowest projected win total on the board. In fact, it's tied with the 2013 Astros as the lowest offered by oddsmakers since I've been tracking these odds in 2001.

The sportsbooks have the Orioles improving by 11 games, likely just because of regression to the mean. It's difficult for any team to lose more than 100 or win more than 100 games. If recent history is any indication, however, the idea that a very bad team will automatically get better isn't warranted. Since 2001 there have been four teams projected by oddsmakers to win fewer than 64 games. Three of those teams won fewer games the next season for an average decline of 2.3 games.The 2012 Astros may be a good parallel. After a modest run of success the previous decade, a 100-loss season finally resulted in a new GM and manager. Jeff Luhnow inherited a terrible farm system and spent the first two seasons rebuilding and generally not caring about wins. The Astros finished under the sportsbooks' low expectations each year. Houston's commitment to fully "tank" is now the model every team is seemingly trying to emulate – to the point where many say only half the league is even trying each season. The Orioles likely need to get worse before getting better. I'll wager $50 that Baltimore wins fewer than 58.5 games.

The Book's Biggest Movers

I've already talked about the Mariners and A's (and considering their season's have already begun, they're likely off the board in most sportsbooks) and how their declines are too in line with the movement in their odds for value.

I think all five teams expected to improve by more than 10 games may be a reach. The Reds did add significant upgrades to their lineup and have a number of young hitting prospects, even if the pitching is still suspect. The trend is upward, so I'll pass on a bet. The Padres did add one of the best players in the game in Manny Machado and have a lot of prospects on the cusp of contributing. The White Sox have a number of prospects also on the cusp of contributing, including Eloy Jimenez who may now be in the majors on Opening Day due to a new contract. I think a jump of more than ten games for either franchise is too much, but I'm not confident enough to make a bet.

The Royals on the other hand are still rebuilding and may need to get worse before they get better. Most of the veterans they acquired are underwhelming (Jake Diekman, Drew Storen and Brad Boxberger and Billy Hamilton) and the starting rotation figures to be one of the worst in baseball. And while their farm system isn't as terrible as some rebuilding teams (21st per ESPN's Law), most of the top prospets are in the lower minors. I'll bet $25 the Royals don't win 69.5 games.

The Book's Non Movers

Basically, the sportsbooks have a lot of teams they think will stay the same. It was similar last year when the sportsbooks projected 15 teams within 3.5 games of their previous year's record. Only 3 of those 15 teams finished within 3.5 games of their projection (though collectively they were only 1.87 wins under their line).

One team that stands out for me on this list is the San Francisco Giants. The Giants improved to 73 wins from 64 wins in 2017. However, the Giants feature an aging core that's far past its prime. New GM Farhan Zaidi is likely to tear down the roster in an effort to rebuild. I'd be shocked if any veteran having a good year, other than Buster Posey, isn't traded for prospects. Meanwhile, the Giants have the 26th best farm system according to ESPN's Law with most of it's strenght in the lower minors, so reinforcements are not on the way. I'll wager $50 the Giants win fewer than 73 games.

Similarly, the Rangers and Blue Jays are rebuilding and likely to be worse before they're better. Toronto gives me pause on taking the under since at some point top prospect Vladimir Guerrero Jr. will be in the majors after he overcomes a oblique injury and manipulation of his service time to get another year of team control. Since many peg him as an immediate top-20 hitter in MLB, he could help slow Toronto's decline. The Rangers however are another team rebuilding that likely needs to get worse before it gets better. Offseason signings of Lance Lynn, Hunter Pence, Logan Forsythe and Ben Revere are not exactly inspiring. The farm system ranks 20th (via Law again) but most of the best are in the lower minors. I'll bet $25 the Rangers don't win 70 games.

Wild Card

Last year I thought a good bet, if anyone would offer it, would be to take the over on a combined 300 wins from the Astros, Red Sox and Yankees (or maybe it was the Indians. Either way, you won.). There's such a divergence in the AL, where arguably only eight teams are trying to win and seven teams are rebuilding or directionless. As a result the large gaps between the top and bottom of the league may continue.

I'd almost advocate a parlay of the over of the Astros, Red Sox and Yankees or maybe all eight teams (though I'm likely down on the Angels chances). Of course a parlay is always a bad bet since you don't get true odds, but the theory holds that it's better to take the over on the top of the league given the paucity of the bottom of each division.

To recap, here are my bets for 2018.

One note: My bets/track record doesn't try to account for the variations in extra juice you need to pay. Most lines are -110, meaning the sportsbook takes about five percent on each bet. The "Vig" tends to be higher on these bets than for single games. Sometimes the vig can vary widely, such as when 2016 Texas Rangers under of 83.5 wins was at -140 (the under was +110). It's another method for the bookmakers to alter how the money is coming in on each side so it gets to their comfort level. Or it's a way to change the odds without moving the win total.

If you are making a lot of bets, this is a serious factor in the math. But I don't bother to take that into account because I'm more focused on the overall wins number for a team perspective. Plus, I forget to keep track of the Vig in early years.

I vary the dollar amounts below as a way to show how confident I am in the bet (the $300 bet on the 2004 Royals is my all-time high), so there are some holes in the math if you added in all the varying vigs.

And why should you care what I think? I've made money 10 of the last 18 years (with one push). Here's the breakdown: