Sticky stuff 101: Everything you need to know as MLB's foreign-substance crackdown begins

Beginning with Monday's games, pitchers will be ejected and suspended for using illegal foreign substances to doctor baseballs as Major League Baseball ramps up its enforcement of an area that has been the talk of baseball in recent weeks.

But the start of MLB's crackdown brings as many questions about how it will work as it does answers to an issue that has led to high strikeout rates and many debates across the sport. How will umpires go about conducting examinations of pitchers during games? What happens if a player is caught? How differently do pitchers and hitters feel about the steps being taken? And how much of an impact will this all have on the product we see on the field?

To help get you up to speed for the start of a new chapter for baseball, we asked ESPN MLB experts Alden Gonzalez and Jesse Rogers to provide an FAQ-style breakdown of how the foreign-substance crackdown will play out across MLB.

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How will umpires enforce MLB's foreign-substance crackdown during games?

Rogers: Pitchers will be inspected after innings and/or when they come out of games. If they're doing something suspicious during an at-bat, they can be checked between batters as well. Their hat, glove and belt will be looked at while the rest of the uniform is also in play if umpires deem it necessary. The one post-examination exception is for closers. They'll be inspected before they pitch to avoid awkward walk-off moments. Umpires will be on the lookout for anything that feels or looks slick or sticky.

Gonzalez: And that is among the many elements that are fascinating about this. The league didn't want to navigate the difficulty of suspending players retroactively based on findings from inspected baseballs, which would have undoubtedly triggered a litany of objections. Umpires, the league believes, have to be the enforcers. Maybe so. But this is asking a lot of those umpires, who are already under such heavy scrutiny with automated strike zones forthcoming. When a pitcher has to exit because he has been caught using foreign substances, umpires will be the ones who will hear it from coaches, players and fans, even though they're merely acting on the league's intentions.

What happens if someone is caught with a substance deemed to be against the rules?

Rogers: He will immediately be ejected and suspended for 10 days with pay. The team cannot replace the player on the roster.

Gonzalez: The memo sent to teams stated that repeat offenders will be subject to "more severe, progressive discipline," though it's unclear what that might actually look like.

How will this impact position players?

Rogers: If they're acting suspicious as they visit a pitcher on the mound, they can be checked out by the umpires as well. Many infielders -- especially during the colder months -- have possessed a grip enhancer just like a pitcher does. As long as they don't assist their own pitcher they probably won't be subjected to a random check. If a position player comes in to pitch, he might need to switch gloves.

Why is this starting on June 21, two months into the season?

Rogers: MLB wanted to gather data before laying down the hammer. The league says it saw more evidence of sticky stuff on baseballs than it first imagined, so it wanted to act before the game devolved into a three-true-outcome experience more than it has. Strikeouts are way up while batting averages have come down even more. The threat of the crackdown appears to be having an impact as June has been a better month for balls in play, although the warmer weather also can play a part in offensive improvements.

Gonzalez: The suddenness of this is still jarring to me. This could've been handled so much more smoothly, either by waiting until the forthcoming offseason to allow pitchers to adequately adjust to throwing the baseball without anything on it or by warning them about an upcoming crackdown before last offseason. The league has known for years that this had become a serious problem, with pitchers venturing outside of sunblock and pine tar to maximize spin rate. Why not push this sooner so that players had months to adjust, rather than force them to go cold turkey in the middle of a season? It's a question a lot of pitchers have been asking.

How do these sticky substances help pitchers?

Gonzalez: The better the grip, the more spin that can be generated on breaking balls and four-seam fastballs, the latter of which use spin to create the "rising" illusion and, thus, produce swings and misses. Four-seam fastballs have essentially replaced sinkers in the modern game, making the use of sticky substances all the more prevalent. Trevor Bauer was conducting experiments on this way back in 2018, when he stated that added stick triggered an increase between 200 and 300 revolutions per minute on 90 mph fastballs.

But that's only part of the story.

The other aspect of this is that the surface of major league baseballs has been found to be inconsistent and, at times, exceedingly difficult to grip. The memo issued to teams stated that "the rosin provided for on the mound ... is sufficient alone to address any serious concerns about grip and control." But that runs counter to what I have heard from several pitchers, who say the balls are often dusty and chalky -- especially when a few days have passed since they were rubbed up -- and are too difficult to grip without a tackier substance.

The league's plan had been to come up with a uniform substance with which to rub up baseballs before the game, replacing the mud that had been utilized since the mid-20th century. Cracking down on everything before implementing that has predictably upset a lot of pitchers.

How much impact will this have on games starting this week?

Rogers: It's doubtful we'll see players ejected and suspended immediately. There's too much attention on the subject right now. But we might see some elite pitchers look a little different than they have previously. That could mean reduced spin rates and hard contact going up -- or just more contact, in general. A further reduction in strikeouts would make league executives very happy.

Gonzalez: Perhaps it's already starting to have an impact. On June 5, our own Buster Olney reported that major league umpires would begin strictly enforcing the use of foreign substances within weeks. At that point, the leaguewide slash line was .237/.312/.396 and the strikeout rate was 24.2%. Over the next 14 days, the leaguewide slash line rose to .248/.320/.416, while the strikeout rate dropped to 23%. It's important to note, though, that offense typically picks up when the weather gets warmer. But the average RPMs on four-seam fastballs was 2,316 from April 1 to June 5 and 2,260 from June 6 to 14. Usually you need RPM drops of 150 to 200 to really notice a difference in the way a baseball behaves. But that was by far the lowest two-week spin rate this year, according to ESPN Stats & Information research.

What are pitchers saying about the crackdown?

Rogers: It depends on whom you talk to. For obvious reasons, those who say they don't use anything are all for the crackdown -- think soft tossers and sinkerball artists. Others are wholeheartedly against outlawing the more innocent use of sunscreen and even pine tar, claiming they need it for grip. Then there's Tyler Glasnow, who says not using anything in his last start led to his injury and will lead to others. Many pitchers are united in believing the league should have waited for the offseason to act.

Gonzalez: The pitchers I have spoken to are surprised the league lumped those who use pine tar or sunscreen in the same group with those who deploy more exaggerated grip enhancers like Spider Tack or Pelican Grip Dip, given that the league -- and its hitters -- have historically turned a blind eye to the former group. Perhaps the league thought it would be too difficult for umpires to make such a distinction during games. But there are potential adverse effects with this plan, too, and one has to wonder whether Glasnow will be the last to blame an injury on the league's sudden enforcement strategy.

What are hitters saying about the crackdown?

Rogers: Many are in favor of it, but some have a soft spot for the sunscreen users. If hit-by-pitches rise above their current level, you'll see a cry for help -- possibly from pitchers and hitters. Good grip helps pitchers with control. That's the argument that has historically been made and will continue to be made. The data might back it up.

Gonzalez: Also, though, this will undoubtedly help hitters gain some semblance of an advantage, and they'll happily take it given how much of an advantage pitchers have gained through analytics. In the words of Justin Turner, a 13-year veteran and player rep: "All we want is a fair playing field across the board for everyone and everyone to have the same opportunities. Whatever the league had to do -- as long as it's fair and it's across the board and it's the same for everyone, I think that's the main goal here."