Shhh! Don't tell anyone, but baseball is changing

This week from Sam Miller: Quiet changes are afoot in the big leagues this season, the Angels' farm system really might be that bad ... and the groundout heard 'round the world. Jon Durr/Getty Images

There are loud changes in baseball and quiet ones. While the topline news about this season has been the continuing march toward three true outcomes (walks, strikeouts and home runs), there are other ways 2017 has been different than 2016, 2015 and in some cases all seasons before. Are these changes real? Are they permanent?

Sacrifice flies are down
The unsurprising development is that sacrifice bunts continue trending down. This is easy to explain: Teams have almost total control over how many sacrifice bunts they lay down, and as managers and front offices embrace data showing many sacrifice bunts are counterproductive, a number of traditional "sacrifice situations" are now appropriately treated as "get-a-hit situations." More surprising, though, is that the sacrifice fly, which involves much subtler shades of intent, is being whittled away.

This year, there have been 0.22 sacrifice flies per game. That's down 12 percent from last year, which was already the lowest rate since 1972. The 2017 rate would be the lowest since 1954, when sac flies were first tracked.

The first question for any early-season developments: Is it just an April thing? Doesn't seem to be. Since 2010, there have been slightly more sacrifice flies in April than in the other five months.

The second question: Are we focusing on the right detail? If, for instance, far fewer runners are reaching third base with none or one out, then the lack of sac flies would merely be the trees in this forest. In fact, there are fewer runners reaching third base with none or one out:

However, even with that decline we see fewer sacrifice flies per opportunity this year:

Is there a plausible explanation given what else we know about modern baseball tactics? The answer here is yes. Pitchers are more skilled at striking batters out -- though, notably, the K rate in sacrifice situations is not up from last year. Less easily explained is that sacrifices per ball put in play are down, suggesting either that pitchers are inducing weaker contact or more grounders in sac-fly situations; that third-base coaches are less aggressive; that outfielders have better arms; or that we've now sliced these numbers so fine that we've got small samples.

Which leads to the fourth question: Will this wash out with a bigger sample? We speculate this one will partly -- there are only 13 "missing" sacrifice flies compared with last year's rates -- but not all the way.

Wild pitches are up.
At 0.38 per game, the league is on pace to set a record. Last year's 0.37 was a record, up from 2015's 0.36 (a record!). For most of the 21st century, the league was between 0.30 and 0.32 per game.

1. April? Partially. Since 2010, there has been a wild pitch every 25.8 innings; in April, though, it's one for every 25.2 innings. Extrapolating from that, we might expect the 2017 rate to drop back to last year's 0.37 per game, though that'd still be enough to match the all-time high. That's notable, too, because ...

2. Right detail? Yes. There are actually fewer baserunners this year, and the league's .313 OBP is the lowest it has been in more than four decades.

3. Plausible explanation? It's hard to block pitches that are thrown harder. The average fastball is 92.12 mph this year, up from 91.79 mph at the same point last year, according to Statcast data.

4. Will it wash out with time? Nope. As long as pitchers are throwing harder, nastier stuff that's harder to hit, it'll be harder to catch.

Ground ball double plays are up.
At 0.81 per game, the GIDP rate would be the highest since 2007, up 5 percent since last year despite fewer baserunners.

1. April? No. Double-play rates have been exactly the same in April as in the other five months this decade.

2. Right detail? Yes. Again, with fewer baserunners overall and fewer balls put in play, we would expect fewer double plays, not more.

3. Plausible explanation? Perhaps. Here's a hypothesis: As the league gets more comfortable with shifts -- which, incidentally, are up again this year -- they might finally have solved the challenge of making sure out-of-position fielders are in position to cover bases with runners on.

4. Will it wash out? Probably. Ground balls aren't up in general, and we're talking about 17 extra double plays leaguewide to date.

Halos: Help wanted

Before the 2014 season, Baseball Prospectus prospect writer (and now Cubs special assistant) Jason Parks summed up the strength of the Twins' farm system and the weakness of the Angels' like this: Even if the Twins lost their top 10 prospects, they'd still have a stronger farm system than the Angels do.

We wanted to see how true that would be. So we took the Twins' top 30 prospects from that winter and removed Parks' top 10. Here's who made up the best of the Twins' rest:

Trevor May
Danny Santana
Max Kepler
• Fernando Romero
• Stephen Gonsalves
Michael Tonkin
• Adam Brett Walker
• Mason Melotakis
Taylor Rogers
Kennys Vargas
• Lewin Diaz
• Randy Rosario
• Luke Bard
• Amaurys Minier
• Travis Harrison
• Niko Goodrum
• Tyler Jones
• Zack Jones
• Roni Tapia
Stuart Turner

The big name there is Max Kepler, who would go on to develop into a top prospect and is now hitting .294/.351/.490 in the middle of Minnesota's lineup. Three others -- Santana, Tonkin and Rogers -- are on the Twins' active roster, and May was an established member of the Twins' pitching staff before undergoing Tommy John surgery this spring. Sixteen of those 20 players are still with the organization, and Romero and Gonsalves have improved their prospect status and are now top-five prospects in the system.

The Angels' farm system at the time, meanwhile, had Cam Bedrosian, who was ranked No. 10 by Baseball America; he's now the Angels' de facto closer and one of the top young relievers in the game. Angels part-time first baseman C.J. Cron and reliever Mike Morin were also in the system. Mostly, though, the Angels traded that group of marginal prospects for any big leaguers they could get: Huston Street, David Murphy, David DeJesus, Cameron Maybin, Vinnie Pestano, Cesar Ramos, Martin Maldonado and Joe Thatcher (among others) were all acquired with the products of that farm system. Of the players sent away, only Diamondbacks reliever A.J. Schugel and Jett Bandy have contributed anything significant to any big league club. (Taylor Lindsey and Kaleb Cowart are among the flops at the top of that system.)

As it stands now, the Twins' group probably is slightly more accomplished than the Angels' group, but the Angels got more out of theirs by trading aggressively. The comparison is far from concluded, though. The Twins might still be reaping the benefits of that farm system's depth for years to come.

The groundout heard 'round the world

Earlier this week, Bill James tweeted:

The ball, of course, would end up traveling farther than 24 feet, but James is right that the hardest-hit ball this year is profoundly disappointing, a groundout to the shortstop at the end of a blowout:

It is what it is, but I'm surely not the only one who wishes the hardest-hit ball of the year was something worth sitting through an advertisement to watch. Our hopes for a more suitable leaderboard leader probably lie with the Yankees' Aaron Judge, a very large rookie who has five of the 14 hardest-hit balls in baseball this year, according to Statcast. On Saturday, he faces Jameson Taillon, whose 95 mph average fastball is the 11th-hardest among starters this year. Nothing against Eric Hosmer, but I'm sick of that groundout.