Expert MLB Betting Picks: Top Monday Predictions for June 30

Written by

Daniel Dobish

Published on June 30, 2025

More Home Runs. Fewer Strikeouts.

Get RotoWire's advanced reports and tools to confidently start your best team.

Custom reports based on your team
Confirmed lineup alerts
Advanced stats to help you choose the right players

MLB Picks Today: Expert MLB Picks for
Monday, June 30

Major League Baseball has a typical abbreviated schedule on Monday, with the San Diego Padres and Philadelphia Phillies battling on MLB Network at 6:35 p.m. ET, and the San Francisco Giants and Arizona Diamondbacks meeting at 9:40 p.m. ET on FOX Sports 1. Let's get started building our bankroll for the second half and beyond!

Cash in on the best sportsbook promos available at the best MLB betting sites this baseball season. The BetMGM bonus code gets new players one of the best welcome bonuses in the industry.

Giants vs Diamondbacks: Expert Betting Tips and Analysis

The Giants (45-39) and Diamondbacks (41-42) kick off a four-game divisional series at Chase Field in Phoenix on Monday, and the game is on FS1.

San Francisco had an unexpectedly difficult time against the Chicago White Sox on the road over the weekend, dropping two of three games. The Giants scored a total of just five runs against a team which has a 4.10 ERA and 1.40 WHIP.

On the flip side, Arizona limps into this crucial set after a three-game sweep at home against the lowly Miami Marlins. The Diamondbacks' pitching staff has had a tough time lately, too, coughing up six or more runs in each of the past four outings, with the Over going 4-0 in that span.

San Francisco turns to ace RHP Logan Webb, who is 2-0 with a 0.00 ERA in two starts against Arizona last season. Meanwhile, Arizona sends out RHP Ryne Nelson, who has allowed just two runs in 15 2/3 IP across his past three outings. The last time the Diamondbacks cashed an Under was a 4-1 win against the White Sox last Tuesday.

While the Diamondbacks have cashed high in five of the past six games, the Giants have cashed low at an 8-4 clip in the past 12 games back to June 17.

In a three-game set in San Francisco May 12-14, Arizona won 2 of 3 games, each by one run as a slight underdog.

Let's back the Diamondbacks catching the run and a half, and we'll go low on the total based on Webb's splits in 2024 against Arizona.

MLB Best Bets for Giants vs Diamondbacks:

Diamondbacks +1.5 (-142 at FanDuel Sportsbook)
Under 8.5 Runs (-115 at DraftKings Sportsbook)

Royals vs Mariners: Monday's Series Opener Insights

The Royals (39-45) and Mariners (43-40) meet in the series opener in Seattle, the first of a four-game set.

Kansas City won two of three games in the first series June 7-9 at Kauffman Stadium. The underdog cashed in each of the games with the Over going a perfect 3-0. In fact, we had an average of 14.0 combined runs per game in the set.

The Royals have skid hard lately, though, winning just once in the past eight games back to June 21, while the Under is 7-1. That's because Kansas City has scored four or fewer runs in seven of those eight games, and it has been shut out twice in the past five outings.

For the Mariners, they took two of three games in Texas over the weekend, but it's been sink or swim on offense. Seattle has scored six or more runs in two of the past three games, but also a total of three runs in three losses since last Wednesday.

Royals RHP Michael Wacha takes the ball for the visitors, while RHP George Kirby is the starter for the Mariners.

The last time Kirby started, he was on the short end of a 2-0 loss in Minnesota Wednesday. The Over is 2-1 in his past three starts, though, while going 9-2 in the previous 11 outings.

Wacha is 4-7 this season across 92 IP in 16 starts, but he has a respectable 3.33 ERA and 1.22 WHIP. Let's go low on the total based on Wacha's splits and Kansas City's struggles lately.

MLB Best Bets for Royals vs Mariners: