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2021 MLB Underdog Betting Report - Moneyline, Runline & Pitcher Records

The Seattle Mariners have been great underdog bets for the 2021 MLB season.

Major League Baseball is back!! Oddsmakers are letting the boys play for the 2021 season and moneyline underdogs are already starting to pay dividends. With MLB historically having the largest win percentage each season for underdog moneylines, it’s time to dive into the numbers for the 2021 MLB Underdog Report.

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We at Odds Shark love to find profitable angles and trends to help bettors approach a grueling MLB season and one of the ways so far in 2021 has been to just blindly bet every underdog moneyline. If you had backed every MLB underdog on the moneyline so far this season with $100 bets (404 games), you’d be up to $4,651.43 in profit. Those profits aren’t as juicy as they had been but the goal in sports betting should be long-term gains, not getting rich quickly.

We will be updating this report with new data weekly all the way through to the final out of the World Series, so be sure to check back frequently.

Joe Osborne is also keeping track of all the MLB First Five Inning betting results from this season and you can find those updated records in his betting report.

All profits listed based on $100 per bet.

2021 MLB Underdog Moneyline Profits

MLB 2021 Underdog SU Records
SituationUnderdog SU RecordsProfits
OVERALL192-212 (47.5%)+$4,651.43
HOME74-74 (50.0%)+$1,870.67
ROAD118-138 (46.1%)+$2,780.75
LAST 3 DAYS20-25 (44.4%)+$139.15
LAST 7 DAYS42-51 (45.2%)+$771.25
LAST 14 DAYS81-100 (44.8%)+$1,077.7
LAST 30 DAYS179-205 (46.6%)+$3,647.34
DAY87-91 (48.9%)+$2,680.48
NIGHT105-121 (46.5%)+$1,970.95

Betting records as of May 3, 2021

With MLB underdogs winning outright 47.5 percent of the time, profits are remaining steady for bettors. If you had backed every MLB underdog so far this season, you’d be up to $4,651.43 in profit. That’s a decent return in four weeks.

Road underdogs are crushing it so far this season at 118-138 SU through 256 games and are holding up their end of the bargain with profits of $2,780.75 for $100 bettors. MLB, unlike what I reported in the NBA Underdog Report, is a bit different than its sports brethren with its home underdogs being less profitable while road dogs are shouldering the load.

With so many games each day, it’s important to look at the splits to see how this MLB underdog trend is faring. For example, over the last week, underdogs are still managing a slight profit and had you started this strategy seven days ago with $100 bets, you’d be up $771.25 with underdogs going 42-51 SU in that stretch.

Picking and choosing your spots while anticipating a regression can sometimes make a huge difference to your bankroll.

2021 MLB Underdog Runline Profits

MLB 2021 Underdog ATS Records
SituationUnderdog ATS RecordsProfits
OVERALL250-162 (60.7%)+$1,267.11
HOME91-63 (59.1%)+$597.66
ROAD159-99 (61.6%)+$669.45
LAST 3 DAYS23-22 (51.1%)-$591.74
LAST 7 DAYS53-42 (55.8%)-$398.96
LAST 14 DAYS110-74 (59.8%)+$116.99
LAST 30 DAYS233-159 (59.4%)+$392.88

Betting records as of May 3, 2021

Personally, I don’t usually bet or recommend bettors play +1.5 runlines for MLB underdogs. The juice is often such a squeeze that bettors likely have to wager more than $100 each time just to make the potential returns worth it and then the team you back could still lose by two runs anyway.

However, the fact remains that if you had blindly bet $100 on the +1.5 runline for every MLB underdog, you would have decent profits, even if they’re not as lucrative as moneylines. When you look at the underdog runline record and see 250-162, that would obviously get bettors excited because an angle is hitting at 60.7 percent. The issue, as I mentioned, is most +1.5 runline odds are -200, or worse in some cases, which seriously negates potential profits. That’s why just taking the moneyline instead of the +1.5 runline in MLB is the more sound investment long term.

Check out the MLB runline report for the best and worst teams on the runline in 2021.

MLB Underdog Report - Days of the Week

DayUnderdog RunlineUnderdog ProfitUnderdog SUUnderdog Profit
Monday25-17 (59.5%)+$43.7317-23 (42.5%)+$111.36
Tuesday40-21 (65.6%)+$589.3533-28 (54.1%)+$1,563.14
Wednesday37-20 (64.9%)+$662.0129-27 (51.8%)+$1,429.09
Thursday34-17 (66.7%)+$702.0926-24 (52.0%)+$1,120.33
Friday29-29 (50.0%)-$923.5920-38 (34.5%)-$1,318.0
Saturday43-30 (58.9%)+$88.5131-40 (43.7%)+$183.46
Sunday42-28 (60.0%)+$105.0136-32 (52.9%)+$1,562.05

Betting records as of May 3, 2021

When one of my followers on Twitter brought to my attention an observation about underdogs covering the spread and/or winning outright in the NBA on specific days, I had to put this to the test for MLB. Generally, I would’ve been dismissive of such an absurd trend since teams/matchups and many other betting factors change each day, regardless of where it falls on the calendar.

Well, I had to eat some crow again on this because certain days just work out better for bettors. For example, if you had blindly bet $100 on every underdog moneyline exclusively on Tuesdays (61 games), you’d be up to $1,563.14 in profit.

MLB Underdog Moneyline Team Report

TeamUnderdog Win %Underdog SU RecordProfit
Red Sox80.08-2863.48
Blue Jays53.38-7359.0
White Sox40.02-3-102.09

Betting records as of May 3, 2021

While it’s still very early in the 2021 MLB season, certain teams are clearly cash cows when tabbed as underdogs and one team that immediately stood out is the Seattle Mariners.

Despite dropping six of their last 10 games, the Mariners are still the most profitable underdogs in MLB as of May 3. They’re now 15-12 SU and had you bet $100 on the Mariners each time they were pegged as dogs, you’d be up to $893 in profit. That number will surely change as the season goes on because the Mariners will likely be underdogs in a lot of their games playing in the American League West.

One team that will likely be vying to be king of MLB underdogs when the season concludes is the Boston Red Sox at 8-2 SU. After recently knocking off the Mets at Citi Field with Jacob deGrom on the mound, the Red Sox are now second in MLB for profits in this spot at $863.48.

As it stands on May 3, there is only one team that has yet to lose as an underdog this season and that’s the Los Angeles Dodgers.

MLB Underdog Starting Pitcher Report

John Means564.04-0 (100.0%)
Chad Kuhl487.03-1 (75.0%)
Chris Flexen480.04-1 (80.0%)
Matt Harvey479.04-1 (80.0%)
Danny Duffy372.03-0 (100.0%)
Jeff Hoffman339.012-0 (100.0%)
Kyle Gibson330.094-2 (66.7%)
Matt Moore328.02-0 (100.0%)
Yusei Kikuchi318.03-1 (75.0%)
Justin Dunn308.03-1 (75.0%)
Kevin Gausman304.02-0 (100.0%)
T.J. Zeuch290.02-0 (100.0%)
Adrian Houser277.02-0 (100.0%)
Brandon Woodruff265.02-0 (100.0%)
Merrill Kelly262.03-2 (60.0%)
Martin Perez260.02-0 (100.0%)
Justus Sheffield257.03-2 (60.0%)
Jesus Luzardo254.02-0 (100.0%)
Aaron Civale250.02-0 (100.0%)
Dylan Bundy243.02-0 (100.0%)
Nick Pivetta235.01-0 (100.0%)
Eduardo Rodriguez230.092-0 (100.0%)
Trent Thornton215.02-0 (100.0%)
Johnny Cueto214.02-0 (100.0%)
Mike Foltynewicz210.03-2 (60.0%)
Andrew Kittredge210.01-0 (100.0%)
Nathan Eovaldi205.242-0 (100.0%)
Kwang Hyun Kim201.152-0 (100.0%)
Trevor Rogers198.02-2 (50.0%)
Zack Greinke195.132-0 (100.0%)
Pablo Lopez190.02-1 (66.7%)
Eric Lauer185.01-0 (100.0%)
Jordan Lyles175.03-3 (50.0%)
Hyun Jin Ryu170.01-0 (100.0%)
Tyler Mahle163.01-0 (100.0%)
Sean Manaea160.01-0 (100.0%)
Zach Davies157.02-1 (66.7%)
Zac Gallen154.02-1 (66.7%)
Julio Teheran147.01-0 (100.0%)
Steven Matz146.01-0 (100.0%)
Michael Wacha146.01-0 (100.0%)
Rich Hill133.02-1 (66.7%)
Alec Mills133.01-0 (100.0%)
Huascar Ynoa132.01-0 (100.0%)
Ian Anderson130.01-0 (100.0%)
Alex Wood130.01-0 (100.0%)
Travis Bergen125.01-0 (100.0%)
Bryse Wilson125.01-0 (100.0%)
Chris Archer123.01-0 (100.0%)
John Gant122.02-1 (66.7%)
Jose Berrios120.01-0 (100.0%)
Taylor Widener117.02-2 (50.0%)
Nick Neidert115.01-1 (50.0%)
Jon Lester115.01-0 (100.0%)
Jack Flaherty113.01-0 (100.0%)
Joe Musgrove110.01-0 (100.0%)
David Peterson110.02-1 (66.7%)
Marcus Stroman108.01-0 (100.0%)
Ervin Santana108.01-0 (100.0%)
Jose Urquidy107.01-0 (100.0%)
Cristian Javier106.01-0 (100.0%)
Kyle Wright103.01-0 (100.0%)
German Marquez103.02-2 (50.0%)
Freddy Peralta100.01-0 (100.0%)
Domingo German100.01-0 (100.0%)
Daniel Ponce de Leon100.01-0 (100.0%)
Madison Bumgarner99.02-2 (50.0%)
Michael Pineda98.041-0 (100.0%)
Tyler Anderson97.02-2 (50.0%)
Taijuan Walker96.151-0 (100.0%)
Elieser Hernandez96.151-0 (100.0%)
Erick Fedde89.02-2 (50.0%)
Joe Ross75.02-2 (50.0%)
Wil Crowe70.01-1 (50.0%)
Michael Fulmer68.01-1 (50.0%)
Casey Mize63.02-3 (40.0%)
Zach Plesac56.02-2 (50.0%)
JT Brubaker52.02-2 (50.0%)
Ryan Weathers51.01-1 (50.0%)
Garrett Richards35.01-1 (50.0%)
Logan Webb32.01-1 (50.0%)
Yu Darvish28.01-1 (50.0%)
Adbert Alzolay20.01-1 (50.0%)
Blake Snell18.01-1 (50.0%)
Luke Weaver17.02-2 (50.0%)
Riley Smith15.01-1 (50.0%)
Ross Stripling13.01-1 (50.0%)
Dallas Keuchel7.01-1 (50.0%)
Zach Eflin5.01-1 (50.0%)
Mike Minor5.01-1 (50.0%)
Alex Cobb5.01-1 (50.0%)
Shane Bieber3.01-1 (50.0%)
Chris Bassitt2.01-1 (50.0%)
Zack Wheeler1.01-1 (50.0%)

Betting records as of May 3, 2021

A lot of handicapping for MLB revolves around starting pitching and how a team performs when a specific hurler is on the mound. Well, certain starters in 2021 have emerged as go-to bets when their team is tabbed as an underdog. Three starting pitchers in particular are raking in the profits for bettors early this season because as good as John Means, Chad Kuhl and Chris Flexen have looked on the mound, the teams surrounding them will rarely be favorites in an MLB game.

Means with the Baltimore Orioles, Kuhl with the Pittsburgh Pirates and Flexen with the Seattle Mariners are the three most profitable starting pitchers in 2021 when their teams are dogs. The Orioles, Pirates and Mariners have played in a combined 77 games when given the underdog label and Means/Kuhl/Flexen have pitched in 13 of them.

With their respective underdog teams managing to go 11-2 SU in this spot when they get the starting nod, bettors have raked in $564 just banking on the Orioles when Means is starting, $487 when Kuhl is on the mound and $480 when Flexen started.

Just remember, this trend is only applicable when these teams/pitchers are underdogs, and doesn’t mean to blindly back the team just because that specific pitcher is on the hill.