What do 316 yards of wool get you? In the world of MLB, about seven pitches. Enter the mystique of the modern major league baseball. But it wasn’t always this way. The science that led to the finely-tuned ball of today is almost nothing like the one from the early days of the game.

In fact, some players are convinced that balls used in the last few seasons are secretly unique, too. Let’s look at the various forms of the major league baseball, how it affected play, and the secrets of the current iteration.

Early baseballs and the dead ball era

In the mid-1800s, as baseball first came to prominence, there was no such thing as a standard baseball. One common example, according to Smithsonian Magazine, involved melted discarded shoe soles wrapped in yarn and leather. Creators also experimented with stitching patterns and materials over the ensuing decades.

Then the 1900s arrived, and with it a standard major league ball. The time from about 1900 to 1921 correlated with a new standard ball that was susceptible to softening over the course of a game. According to Bleacher Report, it led to two decades of small ball play, since the lumpy leather-centered balls made home runs a rarity.

Halfway through the dead ball era, cork-centered balls emerged. These new balls flew further and lasted longer. But without usage rules, they still lost some of their kinetic abilities by the ninth inning. The emergence of the first dead-ball power hitter, Babe Ruth, changed the narrative entirely. To keep up, players dropped small-ball techniques and began taking advantage of these soaring new cork balls.

The anatomy of the modern major league baseball

Today’s MLB has stringent rules on what constitutes an official baseball. As of 2018, MiLB is on board, too, reports Forbes. It must weigh five ounces and nine inches in circumference. There are always exactly 108 double stitches. Then the balls are rolled in a specially formulated mud to help pitchers grip them.

They start with a compressed cork, surrounded by three layers of rubber. Then, four layers of yarn — 316 yards worth — are compressed around the core. Finally, the ball is sealed with tanned cowhide and stitched with the iconic red cotton.

The crucial part that keeps the modern game exciting, though, is another set of rules. Most balls survive about two to eight pitches, usually around seven uses for most, according to Fox Sports. Any malformed parts of the ball are grounds for ejection, with umpires encouraged to be aggressive in their judgment. And balls in the dirt are immediately tossed out of the game.

Did MLB really change baseballs to please crowds with more home runs?

Over the previous two MLB seasons, fans wondered about the possibility of another modern innovation for the major league baseball. At least, that’s what Justin Verlander and other pitchers think. And they might be right.

One consistent report is that the seams feel closer together, meaning the cowhide covering is tightened more than before. Pitchers report feeling this, so FiveThirtyEight and The Ringer combined forces to investigate. They found that newer balls were, indeed, somewhat more tightly wound than older balls.

However, with the materials used essentially identical, the investigation came up inconclusive on whether MLB or another party did this intentionally. Another angle pushing numbers up might simply be a changed approach at the plate.

Tighten seams all you want, hitters are also striking out at increasingly higher rates, according to CBS Sports. Wherever the truth lies, one thing’s for sure: When baseball returns from this unexpected hiatus, we’ll be happy whether we see big home runs or a return to small ball.