Giants vs. Diamondbacks: A Series Preview You Can Actually Understand

What’s Going On Here?

Imagine two kids on a playground. One kid (the Arizona Diamondbacks) was doing really well at the start of recess, but lately keeps tripping over their own shoelaces. The other kid (the San Francisco Giants) was struggling for a while, but seems to be finding their balance again. Now they’re about to play each other — and it’s actually kind of interesting!

Even though the Diamondbacks have had a rough June (winning only 10 of their last 18 games), they’ve been absolutely dominating the Giants this year. They’ve beaten them 6 times with zero losses, and have scored 22 more runs than the Giants across those games. That’s like winning every game by about 4 runs — not exactly close!

But here’s the twist: the Giants are starting to look a little better lately (they’ve won 12 and lost 12 in June). So maybe — just maybe — this time things could be different.

How Did We Get Here?

About a month ago, the Diamondbacks swept the Giants in Arizona. At that time, things looked great for Arizona:

• They had a solid 31-24 record
• They were scoring a lot of runs (10th best in baseball)
• Their pitchers were doing okay (16th best in team ERA)

Their star hitters were on fire:

• Corbin Carroll (hitting really, really well)
• Nolan Arenado (hitting well)
• Ildemaro Vargas (hitting well)
• Ketel Marte (hitting well)

Their pitchers were holding things together:

• Michael Soroka was having a comeback season for the ages
• Eduardo Rodriguez was pitching above average

But that sweep was kind of like the moment in a movie when everything starts going wrong…

What’s Gone Wrong for Arizona?

Since that sweep about a month ago, the Diamondbacks have been one of the worst teams in baseball. Here’s the breakdown:

The Pitching Fell Apart

• Arizona’s record since the sweep: 10-18 (ouch!)
• Michael Soroka got hurt and is now on the Injured List (he can’t play for a while)
• Eduardo Rodriguez has been okay on the surface, but the advanced numbers suggest he’s been a bit lucky
• Ryne Nelson, Merrill Kelly, and Zac Gallen have been absolutely terrible — combining for a 7.08 ERA in 89 innings. To put that in perspective, an ERA above 6.00 is really, really bad. These three have been some of the worst starters in all of baseball.

Important Point: When your three main pitchers are giving up tons of runs, it’s really hard to win games. It’s like trying to hold water in a bucket full of holes.

The Hitting Disappeared

The Diamondbacks’ offense has been almost as bad as their pitching:

• They’ve scored the second-fewest runs in all of baseball over the last 30 days (only 95 runs)
• Their star hitters have fallen off a cliff:
  • Corbin Carroll: Still good, but not the superstar he was
  • Ketel Marte: Still decent, but not great
  • Nolan Arenado: Has been one of the worst hitters in baseball (36 wRC+ — league average is 100)
  • Ildemaro Vargas: Basically can’t get a hit anymore (1 wRC+)

What About the Giants?

The Giants have actually been a little better lately:

• Record since the sweep: 13-14 (not great, but better than Arizona!)
• They’ve scored 133 runs since May 28th (15th in baseball — middle of the pack)
• But here’s the cool part: analytically, they’ve been the #1 offense in baseball over the last 30 days with a 126 wRC+

Compare that to Arizona’s 80 wRC+, and the Giants’ hitting looks absolutely elite.

Almost every Giants hitter has been above average lately. The only ones who haven’t:

• Willy Adames (slightly below average)
• Daniel Susac, Drew Cavanaugh, Eric Haase (well below average)
• Buddy Kennedy (traded to the Mariners, so he doesn’t count anymore)

So the Giants Are Locked to Win, Right?

Not so fast! The Giants have their own problems.

Their Pitching (Besides the Stars) Is Bad

Logan Webb and Robbie Ray have been great, but the rest of the pitching staff? Not so much:

• Team ERA over the last 30 days: 4.51 (21st out of 30 teams)
• They’ve been getting fewer groundballs than usual (40.2% vs. their normal 44.4%)
• The Giants have historically been one of the best groundball teams in baseball since 2002 — they’ve only dipped below 42% twice (in 2020 and 2008)

Important Point: This groundball drop is probably because Logan Webb (their best groundball pitcher) has been on the Injured List. Once he comes back, things should improve.

The Series Details

Projected Starting Pitchers

Players to Watch

For the Diamondbacks

• Geraldo Perdomo: After a slow start, he’s been hitting really well lately (.805 OPS in his last 28 games). He just had a great series against the Rays (6 hits in 11 at-bats with a double and a homer). However, he hasn’t been great at home (.659 OPS) and is only 5-for-22 against the Giants this year.

• Paul Sewald & Kevin Ginkel (Bullpen): Arizona’s bullpen has been bad in June (5.00 ERA), but these two have been excellent. Ginkel has a 2.16 ERA this month, and Sewald has 4 saves. They’re gettable if the Giants are hitting well, but right now they’re pitching great.

For the Giants

• Bryce Eldridge: A potentially great hitter facing a bad pitching staff? That’s a recipe for a big series.

• Heliot Ramos: A power hitter coming back from injury facing a terrible pitching staff? Even better.

• Landen Roupp: He’s been struggling — 0-6 with a 5.12 ERA in his last 10 starts, and the Giants have lost ALL 10 of those games. Yikes.

Fun Extras

• LuJames Groover: He was drafted in 2023 and is known for being really patient at the plate. Also, his name is awesome and sounds like a character from a comedy movie.

• Pavin Smith & Tommy Troy: These two are predicted to annoy the Giants at least once during the three-game series. Sometimes the unexpected players make the biggest impact!

Summary

Here’s the simple version:

1. The Diamondbacks owned the Giants earlier this year (6-0 with a +22 run differential), but that was a month ago.

2. Arizona has fallen apart since then — their pitching is terrible (three starters combining for a 7.08 ERA) and their hitting has disappeared (second-fewest runs in baseball over the last 30 days).

3. The Giants have been improving — they’ve been the #1 offense in baseball over the last 30 days by advanced metrics, and almost all their hitters are performing above average.

4. But the Giants have pitching problems too — outside of Logan Webb and Robbie Ray, the staff has been below average, and Webb is currently injured.

5. This should be a competitive series — even though Arizona dominated earlier, both teams are in very different places now. The Giants’ hot hitting against Arizona’s cold pitching could make for some interesting games.

FAQ

Q: Why have the Diamondbacks been so bad lately?
A: Their three main starting pitchers (Nelson, Kelly, and Gallen) have been some of the worst in baseball, and their best hitters (Arenado and Vargas) have stopped hitting almost entirely. When both your pitching and hitting fail at the same time, losses pile up fast.

Q: What does "wRC+" mean?
A: It’s a way to measure how good a hitter is. 100 is exactly average. Above 100 is better than average, below 100 is worse. So a 126 wRC+ (like the Giants recently) means they’ve been 26% better than the average team. A 36 wRC+ (like Arenado) means he’s been 64% worse than average — really bad.

Q: What’s an ERA?
A: ERA stands for Earned Run Average. It tells you how many runs a pitcher gives up per 9 innings. Lower is better. A good ERA is under 4.00. A bad ERA is over 5.00. Arizona’s starters have a combined 7.08 ERA, which is really, really bad.

Q: Why do the Giants keep losing when Landen Roupp pitches?
A: Sometimes a pitcher can pitch okay (his FIP of 3.08 suggests he’s been a bit unlucky) but the team just doesn’t score any runs behind him. The Giants lost all 10 of his recent starts, which means the offense didn’t show up when he was pitching.

Q: Will Logan Webb’s return fix the Giants’ pitching?
A: It should help! Webb is their best pitcher and one of the best groundball pitchers in baseball. His absence explains why the team’s groundball rate has dropped recently. Once he’s back, the pitching staff should look more like their normal selves.