MLB Best Bets Today March 31
We’ll have 28 of the league’s 30 teams in action on Tuesday, as the Royals and Twins series takes a break in case there was bad weather on Monday for the KC Home Opener. We’re very deep into rotations now, as we’ve got some guys making their second starts, but we’ll see a lot of fifth starter types on the bump tonight. And I do mean tonight, as our first pitch of the evening isn’t until 6:35 p.m. ET.
I’ll be posting my daily best bets Monday-Saturday with a Sunday Night Baseball preview on Sunday, as all the day games make it tough to get something out with lead time out here in Las Vegas. All lines are from DraftKings and are current at the time of publish. Please take the initiative to SHOP AROUND for the best odds. It matters. A lot.
One new offering this baseball season is our Opta AI Player Prop Projections. They are available to everybody now, but will soon be for VSiN Pro Subscribers only, so you can check out our current offers here. Zachary Cohen will be using those projections and his own handicapping to write up MLB player props.
Greg Peterson will have his best bets posted the night before and you can also check out his daily lines to see what looks to be off-market. Steve Makinen has also released his updated Bullpen Betting Systems and DraftKings Splits Systems, plus he’ll have a daily analytics report.
Feel free to use my opinions and thoughts, as well as our suite of MLB Betting Tools, including the DraftKings and Circa Betting Splits, Steve Makinen’s Daily Ratings, Greg Peterson’s Daily Lines, the 1st 5 Innings Analyzer, and Umpire Stats. Check out our new MLB tools powered by Ballpark Pal: Strikeout Projections, Park Factors, and YRFI Report.
That’s a lot of coverage and we’ll be doing it all season long. We’re happy to have you along for the ride.
Here are the MLB best bets today for March 31:
Chicago White Sox at Miami Marlins (-156, 8.5)
6:40 p.m. ET
Back-end starters take center stage here, as the White Sox send out Erick Fedde and the Marlins counter with Janson Junk. Fedde is back with the Pale Hose after a really rough 2025 season in which he was on three different teams, starting with the Cardinals before ending up with the Braves and then Brewers. Fedde posted a 3.11 ERA with a 3.77 xERA and FIP in 121.2 innings with the White Sox in 2024 before being traded to the Cardinals, where he had a 3.72 ERA with a 4.18 xERA and a 4.05 FIP.
He pitched 141 innings, 101.2 of them with the Redbirds, posting a 5.22 ERA with a 5.89 xERA and a 5.13 FIP. It was not a good season for Fedde, who saw his K% drop, BB% rise, and some major LOB% regression. Now he’s back with Chicago and had some decent results during Spring Training, cutting back on his cutter usage after opposing batters hit .315 with a .570 SLG on that pitch. They hit .262 with a .470 SLG the year prior with the White Sox, so we’ll see if they can fix what ailed him last season.
He also had really poor results on his sinker, yielding a .313 BA with a .458 SLG. In 2024 with the White Sox, he allowed a .257 BA with a .366 SLG. I think that’s among the reasons why he opted to go back to the White Sox as a free agent this past winter on a $1.5 million “prove it” deal. With an increase in SL% in the spring, albeit in a small sample size, he generated more Whiffs and more chases. We’ll see if those things carry over, but they seem promising.
Michael Baumann of FanGraphs wrote a phenomenal piece in January about Junk, who had quite the 2025 season. It should be noted that Junk had a 4.53 ERA over 87.1 innings of work as a starter and allowed a .423 SLG last season, while posting a 2.78 ERA over 22.2 innings as a reliever, pitching to a .247/.258/.294 slash. Junk’s best attribute is that he doesn’t walk anybody. His second-best attribute is that he keeps the ball in the park. But, he did really struggle to turn lineups over as a starter and I think the White Sox can exploit that.
Also, Junk had a tough Spring Training period. He sprained his ankle early on and was brought along slowly, topping out at 50 pitches in his Mar. 21 outing against the Cardinals. In four spring starts, he threw 1, 2, 2, and 3 innings, allowing 10 runs on 14 hits in those eight innings. I’m sure he threw something on the back fields or a sim game in between that last start and this one, but still. Not a lot of confidence exiting the spring.
Not only will I take my chances on the White Sox, who are off to a decent start offensively outside of a 35.3% K% that should drop here against Junk, who isn’t a big K% guy, but I was also looking at Junk Under 14.5 Outs Recorded at a really good plus-money price. The weird lead-up to the season paired with an inability to turn lineups over last season (.246 wOBA first time through, .346 second time, .364 third time) pushes me in that direction. Unfortunately, by the time I was ready to publish, DraftKings moved the line to 15.5 and the Under was -181. If it goes back to 14.5, I like Under 14.5 at the big plus-money price.
Picks: White Sox +129
New York Mets (-163, 8.5) at St. Louis Cardinals
7:45 p.m. ET
I am buying stock in Kodai Senga. The Mets right-hander saw a significant velocity spike in Spring Training and also increased the usage of his slider. Clearly he’s working on that pitch and threw his ghost fork less in hopes of staying healthy and being ready for the season. His slider generated a 41.7% Whiff rate last season. Perhaps it was more sweeper than slider, we’ll have to wait and see, as the sweeper was not an effective pitch for Senga last season, but his uptick in velo suggests that he’s healthy and that’s a huge thing.
Senga had a 2.98 ERA with a 3.90 xERA and a 3.63 FIP in 2023 and a 3.02 ERA with a 3.96 xERA and a 4.12 FIP last season. What was maybe the most impressive thing this spring is that he only walked one out of the 35 batters that he faced. He had an 11.4% BB% in 2025 and an 11.1% BB% in 2023. We’ll see how sustainable that improvement is. The Cardinals have only walked in 6.6% of their plate appearances this season, so maybe this isn’t the best data point, but it will be a data point nonetheless. If Senga does struggle with his control, it’s a bigger red flag given the matchup.
With the altered arsenal, Senga got a 36.8% Chase Rate in the spring and more swings and misses in the zone. He had a CSW% (called + swinging strike percentage) of 29.8%, which is bordering on elite and more like what he had in Japan and in 2023. I’m expecting big things.
I never expect big things from Andre Pallante. He gets more outs than you would expect, but regression hit last season. After posting a 3.78 ERA with a 3.52 xERA and a 3.71 FIP thanks to a very low home run rate in 2024, his HR/FB% nearly doubled in 2025, as he posted a 5.31 ERA with a 4.30 xERA and a 4.68 FIP. He’s an extreme ground ball guy with a really poor K% and too high of a BB%. Just not a profile that I like at all.
Pallante’s Spring Training results were fine, but he was down about a full mph on his fastball. Maybe it’ll add a little more movement to his sinker, but he’s working with a thin margin for error to begin with and his stuff profile is really subpar.
The Cardinals bullpen has had a really rough time so far with a low K% and a high BB% and there just aren’t a lot of exciting arms out there. The Mets have the big edge on the pitching side in both areas today and also have the better lineup. I’d rather take run lines with road teams because I know that they’re going to bat at least nine times, as opposed to a home team, who may only bat eight times and miss a chance to score runs.
Pick: Mets Run Line -1.5 (+104)
San Francisco Giants (-143, 7.5) at San Diego Padres
9:40 p.m. ET
Logan Webb makes his second start of the season while German Marquez makes his first and it will also be his first not as a Colorado Rockie. Marquez is the focus of my handicap here, as he struck out 17 batters over his final two Spring Training starts against the Mariners, going 5 and 4.2 innings, respectively, while throwing 78 and 81 pitches. In those two starts, Marquez threw over 65% of his pitches for strikes.
He’s been heavily leveraging his curveball this spring. We all know that pitching at Coors Field is a nightmare for a pitcher and Marquez did it for a decade. What people don’t talk about enough is the Coors Field Effect on the road. Because pitches do way different things than they do at home, it can be really hard to throw with conviction and confidence. It isn’t just that Coors Field impacts you in home starts. It has a major impact on the road as well.
The Padres have a really strong pitching coach in Ruben Niebla, who taught Marquez some “things he didn’t know” in camp. That article was written on Mar. 12 after Marquez allowed six runs and walked four over 1.2 innings against the Royals. In his next two starts, he walked three and had those 17 strikeouts.
So far this season, the Giants offense has struggled. They’ve run into the Yankees and Padres, so some very good pitching, but they have a .154/.230/.211 slash with a 25.2% K% and a 7.4% BB%. Marquez is following Walker Buehler, who only went four innings yesterday, so manager Craig Stammen will be looking for some length.
We can’t quantify this, but it has to feel good for Marquez to make a home start at Petco Park. He has to be more comfortable there than pitching at Coors Field. In 11 starts and one relief outing there, he has a 4.88 ERA, but, remember, that’s with the Coors Field Effect. He still has 71 K in 66.1 innings.
I’m going to ladder Marquez strikeouts in this start. Using DraftKings odds, 4+ strikeouts is -106, 5+ strikeouts is +211, 6+ strikeouts is +461, and 7+ strikeouts is +1020. That’s as high as DK goes, but a new look arsenal for Marquez, with his curveball that had a 36.8% Whiff Rate last season and should be even better with higher spin rates away from Coors Field, should yield some strikeouts and more swings and misses. He had a stellar 79.4% Z-Contact% in camp and a 15.3% SwStr% overall.
Picks: German Marquez Strikeout Ladder – 4+ (-106), 5+ (+211), 6+ (+461), 7+ (+1020)
