Baseball Bets and Odds

Baseball was a statistician and probability expert’s sport early on and, after horse racing, was what popularized sports betting. The standard listing for baseball bets (shown in the following figure) shows a handful of key pieces of data:

• Time/Date: When the first pitch is schedule for each game.
• Rotation numbers: The unique identifier for each side of a baseball bet.
• Teams and starters: The away team is always listed on top, and the home team is always listed on the bottom, with projected starters (and sometimes whether they are right- or left-handed).
• Opening odds: This is optional, but bookmakers sometimes show the opening moneyline and total. You can’t bet on those numbers anymore, but it can give you a feel for where the betting markets are leaning when you compare the opening numbers with the current odds.
• Current moneyline/total: At a minimum, a baseball odds listing should show the moneyline odds for the favorite (with a negative 3-digit number), and the game total (which will be somewhere between 5 and 15).

The baseball moneyline

By now you’re familiar with the moneyline. A moneyline bet is a bet on a team to win the game. It doesn’t matter by how much; it doesn’t matter if it’s in 9 innings or 19 innings.

To split the betting action between teams of differing quality, oddsmakers have two choices:

• They can handicap one team by including a point spread. Betting on either side will be close to an even-money 11/10 bet, but the final score is adjusted by a certain number of points to determine the winner of the bet.
• The alternative is the moneyline, where the final score of the game indicates the winner, with no point or run adjustments, but the payout schedules are different depending on whether you bet on the favorite or the underdog.

There are different explanations for why baseball doesn’t operate with a point spread. One theory is that margin of victory in a baseball game has less to do with the quality difference between the two teams. Another is that overall variability of the game makes it more difficult to attach a spread to. Historians point out that after horse racing, baseball is the original bettors’ sport, and by the time the point spread was invented in the 1940s, there was enough accumulated knowledge and tradition in offering odds on baseball bets that the points spread simply wasn’t necessary.

Either way, a moneyline is a moneyline. Baseball moneylines are no different from any other moneyline: You need the team you bet on to win the game if you want your bet to pay off.

Moneyline encoding

The moneyline of a baseball game comes with several key pieces of information. Let’s consider a baseball game where the home team is listed at –110 and the road team is listed at +100:

• The home team is a slight favorite. The break-even winning percentage for a bet placed at –110 odds, as you know by now, is 52.4 percent. (To calculate breakeven rate on a negative (favorite) moneyline, divide the line by itself less 100 (–110/–210).
• The break-even percentage on the underdog (+100) is 50 percent.
• The bookmaker’s vigorish, or theoretical hold, is about 2.3 percent. A moneyline by itself does not tell you how much vig is being charged by the bookmaker; you need both the favorite and the underdog moneylines to determine what the vig is.

There are no ties in baseball (except in the occasional All-Star game). Your moneyline bet is on the final result of the game, including extra innings (if they are necessary).

Win-loss record perils

If you’re a moneyline bettor in baseball, you can’t judge your success by looking at your win/loss percentage. If you bet on every baseball team with a –170 moneyline in the 2019 season, you would have won 62 percent of your bets! That sounds like a lot of winning, right? Let’s do a quick calculation to see if you would have broken even:

Since we’re looking at bets in the past, we know the actual winning percentage of the bets (62 percent). What we’re interested in is the break-even winning percentage of bets at a –170 moneyline. If those 2019 bets won at a higher rate than the break-even winning percentage, it means they would have been profitable. If the actual winning percentage is below the break-even rate, they would have lost money.

For a favorite, the break-even winning percentage is the moneyline (–170) over itself minus 100 (–270). Here’s the calculation:

–170/–270 = 62.9 percent

So you have to win 62.9 percent of –170 bets to make a profit. That should make sense to you since every time you lose a –170 bet, you’re losing $170 (or $17 or $1.70), and every time you win that bet, you only win $100 (or $10 or $1, respectively). Winning less than 62.9 percent means you’re losing money, and that’s just what would have happened in 2019 had you bet on every single –170 favorite. It might feel strange to win 62 percent of your bets and lose money, but since 62 is less than 62.9, that sad fate is what would have befallen you.

The flip side of that is that if you’re an underdog bettor, it feels strange to win less than 50 percent of your games and be profitable, but that’s what happens sometimes. In 2018, if you had bet on the Marlins every time they were +250 or greater underdogs, you would have won 2 and lost 5. But because those occasional payoffs are worth so much more, that 2–5 record would have also netted you a +14.3-percent ROI.

Point spread bettors can generally tally up wins and losses and judge whether they’ve been successful or not. And the point spread gives you an explicit message, “The betting market thinks Team A is 6 points better than Team B.”

There are no such signposts when you’re a moneyline bettor. When wins and losses become less meaningful, you are forced to think in terms of win probability, ROI, and returns. But don’t be afraid: With a little experience, you’ll learn to calculate in your head. When you see a moneyline on a baseball game, you’ll be able to do a quick mental calculation on the implied odds and decide whether they match your expectation on the outcome.

Total runs bet

Bookmakers offer the typical total bet on baseball, and it works just as you’d expect. The oddsmaker sets a number of total combined runs in the game. Bet the over and you’ll need the teams to score more than the total. Bet the under and you’ll need the pitching to dominate to the point that the total scored runs is less than the total.

Bookmakers offer baseball totals as straight 11/10 bets with –110 odds on either the over or under. And as you might expect, baseball totals are offered in increments of 1/2 runs.

As with football and basketball, any extra game play is included in your total bet. In other words, extra innings count toward your total. If you’ve bet under 8.5 and the 9th inning finishes at 4–4, you’ve got a losing ticket, because the game will continue until one team tops the other.

Run line bet

Since oddsmakers don’t offer a point spread in baseball, there’s no such thing as a standard 11/10 side bet with –110 odds. But Major League Baseball obviously has teams with wide quality differences, and sports books realized long ago that some bettors don’t find extreme moneylines appealing. Favorite bettors don’t get enough payoff to make it worth it, and underdog bettors start to feel like they’ve bet a longshot prop, where the payouts are handsome but rare.

The result was the run line. The run line is like a hybrid between a point spread and a moneyline, and it operates according to these rules:

• A favorite run line bet means a –1.5 handicap is applied to the final score.
• A favorite run line bet is offered at odds equivalent to a moneyline bet on the favorite plus about 80 to 110 points.
• An underdog run line bet means a +1.5 handicap is applied to the final score.
• An underdog run line bet is offered at odds equivalent to an underdog moneyline bet minus about 80 to 110 points.

When oddsmakers tweak your chance of winning, they make an equivalent adjustment in the payout schedule to maintain the same level of risk and return. Spotting the underdog a run and a half means that run line bet is more likely to win, but, as you would expect, the bet pays less in the event of a win. And it works in reverse for the run line favorite. These adjustments allow the bookmaker to maintain a level of profitability while offering bets that appeal to bettors’ different tastes and appetites.

As always, examples pave the path to comprehension. This table shows a pair of games with the moneyline odds listed alongside the run line odds: The Phillies are favored in the first game, as evidenced by the lower moneyline. If you bet the Phillies run line, you take on a –1.5 handicap for the game’s final score, but in exchange, your payout schedule improves from –185 to +110. If you bet $1 at –185 odds, you profit 54 cents. With the run line bet, your $1 bet makes a $1.10 profit. In this case, the odds shifted 95 cents in your favor from –185 to +110.

If you like the Marlins run line bet, you’ll get +1.5 runs added to your final score, but you lose a full dollar on your odds, from +170 to –130.

The second game is illustrative because the teams are listed as even in terms of moneyline. But the oddsmaker always picks one team to be the run line favorite and one team to be the run line underdog.

Bookmakers take a variety of approaches on baseball odds. Some offer low-vig betting where the theoretical hold is as small as 5 cents. (For example, a moneyline favorite is listed at –105, and a moneyline underdog is listed at +100.) Some bookmakers offer noticeably better odds on favorites at the expense of underdogs, and others, vice versa. While the run line handicap is always 1.5 runs, the odds differential — that is, how much the moneyline odds increase or decrease for the run line — can vary as well.

The lesson is that regardless of your baseball bet, you should (appropriately) have at least 3 outs! That is, make sure you have betting options so that you can get the best odds possible on your bet.

The moneyline favorite always gets a –1.5 run line handicap, and the moneyline underdog always gets a +1.5 run line handicap. In cases where the moneyline odds are completely even, the bookmaker picks one side to be the favorite.

If you’re curious about how often the run line comes into play, here’s the breakdown of the 2019 season:

• Favorites won 1489 games and lost 918.
• Of those 1489 games, favorites won 376 by just 1 run, so the moneyline favorite bet won, but the run line bet would have lost.

And 2019 is in line with historical averages. Assuming you pick a winning favorite, they’ll win by exactly one run about a quarter of the time.

Baseball’s “ACTION” condition

Because starting pitchers are so central to the outcome of a baseball game, most side bets (money line, run line, and 5 inning line) are conditional. Look at the moneyline and total odds for this game: The default moneyline bet on the Astros/Rays game is called a listed starters bet. That means your bet is conditional on the starting pitchers listed with the bet actually starting the game. To be specific, a bet on the Astros is only valid if both Justin Verlander and Diego Castillo start the game. Technically, oddsmakers consider it a start as long as the listed pitcher takes the mound and throws at least one pitch.

When you make a baseball bet, you’ll see specific language on your betting ticket or on your online betting receipt that states both starters have to play for the bet to have action. If either pitcher fails to start, the bet is called no action. No action means your bet is effectively cancelled. Bettors at live bookmakers should take their ticket back to the counter, and their bet gets returned. If you bet online, your wager will be returned to your account automatically. There is no juice or fee charged on a no action bet; it’s treated like any other push.

In addition to listed starter bets, many bookmakers offer the option of placing an action wager on baseball. If you choose an action bet, your money is on that bet, regardless of any changes to the starting pitching. But there’s a catch: The bookmaker reserves the right to change the odds if there’s a pitching change.

In the example above, if you had checked the "action" box when you made your bet on the Rays, you’d accept that should Verlander and Castillo both start, your moneyline odds would be set at +210. And that makes sense, as anyone who saw Verlander play in 2019 knows he was a hard man to break, so if the Rays were to do it, you’d get rewarded for your Tampa faith.

Now consider the scenario where Verlander pulls a hammy in warmups and the Astros turn to an untested rookie to start the game. The chances of Tampa winning just went way up. Bookmakers aren’t willing to accept that kind of risk in baseball, so there’s no way they’ll pay you +210 on a fourth-rate starter subbing in for Verlander.

If you had taken a standard bet, Verlander’s absence would cancel your bet. But if you took an action bet, your payout schedule changes to reflect how the betting market would otherwise feel about this pitching change. An action bet means you’re still in on the Rays, but the bookmaker gets a chance to reset the odds and payout schedule for the ticket you hold.

There are very few circumstances where advantage bettors would consider placing an action wager as a +EV play. Action wagers are for fans of a team, or for people watching a big game on TV, who don’t care all that much about who’s on the mound or what the odds are. There is money to be made betting baseball, but not through action wagering.

There are virtually no other circumstances where you don’t get paid the odds stated on your betting ticket in sports betting. Bookmakers protect themselves from big swings in win probability for a given team by either halting betting altogether on a game with a big injury question mark or circling the game.

It’s slightly out of fashion these days, but when a bookmaker offers a circled game, it means there is incomplete information on injuries or playing status of one or more key players. A circled game means you can still bet on it, but at reduced limits.

9 divided by 2 = 5 inning lines

There’s no such thing as halftime in baseball. Sure, the middle of the 5th inning is halfway through the game, unless it isn’t, when the home team is winning and doesn’t bat in the bottom of the 9th.

Most bookmakers now offer their version of a halftime line on baseball games called the 5-inning line. As you might expect, the 5-inning total is around half of the game total. The moneyline usually lands very close to the game moneyline as well. The run line has a slight difference: Instead of a standard –1.5/+1.5 handicap, the 5-inning run line is -.5/+.5, but like its full-game cousin, the 5-inning run line is a derivative of the moneyline. All 5-inning bets resolve once the home team has made 3 outs in its half of the 5th inning.

The average innings pitched per start is around 5.5, so as you would expect, the 5-inning moneyline is a much more pure reflection of the two starting pitchers than the game moneyline. It’s very rare for a starter to pitch a complete game, so game moneylines have to account for bullpen and closer quality in addition to the starter.

Baseball’s 5-inning results are tightly correlated with the full-game results. The 5-inning leader goes onto to win the full game 7 times out of 8. For total bets, games flip-flop a little more often; a 5-inning under ending with a full game over (and vice versa) happens 1 game out of 6.

Like other derivative bets, bettors might find some opportunity in monitoring full-game odds against 5-innings odds for situations where one reacts to news and another doesn’t. For example, if word comes out before the game that one of the team’s big sluggers is a scratch for the game, you might see the game total drop by a full run as bettors flock to the under in light of the diminished offensive firepower. In theory, that same loss of offensive firepower would be felt in the first 5 innings as well, so the 5-inning total should dip by a half-run just like the full-game total did. But often that’s not the case.

But because full-game odds get more attention from bettor than 5-inning odds, the latter is often less responsive to market forces, even though the two results are highly correlated (see preceding paragraph). If the market correctly downgrades the full-game total by a run, the 5-inning total should shrink by a half run. But often it doesn’t. That’s a classic +EV opportunity for a 5-inning under.

It’s something akin to the market getting new information that causes a certain stock to rise. If the market has determined that company is suddenly more valuable than they thought previously, then the preferred stock, call options, and other associated derivative investments should go up too. So if the betting market thinks there will be fewer runs scored, all bets based on run scoring should reflect that new valuation.

Other common baseball bets

Beyond the “big 3 bets” (moneyline, run line, and total) and their derivatives, most online casinos offer a smorgasbord of prop bets, but the most common are as follows:

Team scoring total

Bettors can wager over or under a team reaching a certain score:

Rockies at Rangers — Team Run Total

In this example, there are 4 possible bets on offer. The Rockies team total is 4.5, and a bet on either the over or under has implied –110 odds. If the Rockies score 5 or more, your over bet wins and the Under bet loses. If the Rockies score 4 or less, the under wins and the over loses. That result happens regardless of the Rangers score, and regardless of whether the Rockies win or lose. All that matters for this bet is how many runs the Rockies score at the end of the game.

The Rangers’ team total works the same way. In this example, the bookmaker is trying to balance action toward the under 5.5 side of the bet by making the over bet slightly more expensive relative to the under. As you know by now, if the action gets too lopsided on the over, the bookmaker might increase the Rangers’ team total to 6.

Team total bets are good alternatives to betting sides (moneyline and run lines) or overall game totals when you have a good feel for one side of the pitcher vs batter matchup, but not the other.

Will there be a score in the 1st?

This is a binary yes/no bet with moneyline-type odds, given like this:

Rockies at Rangers — Will either team score in the 1st inning?

The bet is decided as you might expect. If you bet "NO" and the 1st inning goes in the books with the score 0–0, you win. Any other score and your bet wins, regardless of who scored, and how much they scored.

Odds for this bet are based on the quality of the leadoff hitters and early-game pitching tendencies for the starters. Some great starters (Yu Darvish comes to mind) are prone to give up runs early and then settle in.

Some notes on 1st-inning scoring to help you bet:

• If you’re wondering, there’s a run scored in the 1st about 52 percent of the time overall, so odds for each side will hover close to even, with occasional forays into 2-to-1 territory for games predicted to be shootouts. The top teams in terms of 1st-inning scoring percentage are normally between 35 percent to 40 percent by the end of the year.
• 1st-inning scoring is largely a function of overall runs scored, but you’ll see cases where bad offensive teams appear at the top of the 1st-inning scoring percentage rankings; they have a knack for scoring early even though they don’t score as much late. Teams with productive hitters batting first, second, and third sometimes lack quality throughout their lineup, so are more likely to be at the top of the rankings in terms of 1st-inning runs without owning other offensive categories. The reverse can also be true where high-output teams fail to score in the 1st.
• When betting on the 1st inning, consider the manager’s approach as well. Some like to scratch out runs one at a time instead of waiting for a big rally. If a manager likes to bunt, steal, hit-and-run, you’ll see a higher percentage of runs scored in the early innings when the top OBP (on-base percentage) guys bat.
• 1st-inning run-scoring consistency is largely predictable during the season. For the handful of seasons I analyzed in the late 2010s, the leading teams in 1st-inning scoring 8 weeks into the season were still near the top of the list by the end of the season. For example, in 2019, 8 of the top 10 1st-inning scoring teams at the halfway mark ended the year in the top 10. The starting pitchers are a different story though. The starting pitchers leading the league in 1st inning runs allowed are much less likely to be on the list in the second half of the season.
• Further analysis needed: There’s an opportunity for bettors if they can identify those teams that have lost their 1st inning punch. In 2019, the Dodgers and the Mariners were scoring in the 1st inning regularly at the halfway mark, but they fell of greatly and landed out of the top 10 in 1st-inning scoring percentage by the end of the year. If you could identify the factor or factors that led to the drop-off, you could get out ahead of the market and bet "NO" on runs scored in the 1st at advantageous odds.