Timothy R. Smith is a former editorial aide for Book World

Follow baseball long enough, and you are bound to encounter moments of revelation. I had such a moment in 2010, when Washington Post sports columnist Thomas Boswell wrote about the importance of paying attention to the pitch count.

“The count is where the strategic heart of the game is found,” Boswell wrote. “That’s where every iota of study and intuition about your enemy comes into play.”

Pay particular attention to Strike 2, Boswell explained. “In every at-bat last season that reached a two-strike count, the MLB average was .186, with pathetic on-base and slugging averages of .259 and .283.”

“Smart Baseball,” by Keith Law (William Morrow )

I never watched baseball the same way again.

I had another such moment reading “Smart Baseball,” when Keith Law, a baseball writer for ESPN, examined the probability of scoring in every “base-out” scenario, situations involving runners on specific bases with a specific number of outs. With no one on base and zero outs, a team in 2015 would score a run just over 26 percent of the time; with the bases loaded and none out, a team in 2015 scored a run nearly 89 percent of the time.

The run expectancy table gets to a major shift in how baseball is analyzed. In the old days, the most important thing a hitter could do was hit. Batting average, runs batted in and runs scored measured a player’s ability to hit.

But things have changed: “A hitter’s job is to not make an out,” Law writes.

The fewer outs a hitter makes, the higher the probability a run scores.

“The hardest thing for any offense to do is to put a man on base,” Law writes. He cautions that teams should be judicious in stealing bases (unless a runner has a success rate above 75 percent) and that sacrifice bunts usually diminish scoring chances. On-base percentage, not batting average, is the core stat today.

“Off Speed,” by Terry McDermott (Pantheon)

“In MLB history,” Law writes, “the correlation between team OBP and team runs scored per game is huge — stronger than the correlation between team batting average and team runs scored.”

Law derides the statistics for pitcher wins (“dumber than a sack of hair”) and closer saves (“perhaps the most ridiculous of all of the traditional stats because it has actually changed the way the game is played — unequivocally for the worse”). There’s no such thing as a clutch hitter (“if you’re a good hitter, you’re a good clutch hitter, and if you’re a good clutch hitter, you were just a good hitter to begin with).”

Law examines the advanced stats: on-base plus slugging, batting average on balls in play and wins above replacement, the mumbo jumbo stats that old fans love to bemoan. He also explores where the game is going, including StatCast and advanced measurements for defensive play.

What’s most impressive about “Smart Baseball” is that, despite a constant flow of statistics and terms such as “run expectancy matrix” and “range factor,” it never gets confusing. Law makes this possible through an engaging, sardonic style that feels like a friend explaining math with jelly beans.

While “Smart Baseball” will teach you how to be an intelligent fan, Terry McDermott’s little gem, “Off Speed,” captures how to watch the game with the heart. I loved, loved, loved this book.

“This is what this book is about,” McDermott writes: “how pitchers fool, or try to fool, hitters, and how this has evolved for more than a century.”

He follows the course of a single game, Felix Hernandez’s perfecto against the Tampa Bay Rays on Aug. 15, 2012. In nine chapters, one for each inning, he examines how Hernandez and his catcher, John Jaso, befuddled the Rays. Each chapter also examines a different pitch: the fastball (“the located fastball remains the best pitch a pitcher can throw”), the curveball, the sinker (“the rate of home runs hit on low and outside pitches is nearly zero”), how each pitch was developed and how they are used in the game.

McDermott also examines his lifelong love of the game, playing barnyard ball as a kid in Iowa, helping his father maintain an independent league field by dowsing the infield dirt with gasoline and retrieving foul balls hit to the grandstands.

“Out-of-town kids invariably tried to keep the balls if they got them, and this was not allowed,” McDermott writes. “I chased kids halfway across town and fought when fights were inevitable.” He was paid 50 cents a night.

He falls for the Seattle Mariners while listening to the great Dave Niehaus call a game. And he introduces his daughter to the game.

I do wish, however, that McDermott had picked a different game to follow. Short of the exceedingly rare 20-strikeout game (hello, Max Scherzer!), the perfect game is pitching’s greatest performance. There have been only 23 in major league history. But since a runner never reached base in Hernandez’s game, McDermott never explores the art of keeping a runner from stealing or the deception of concealing signs from a runner at second. Or, most important, how a pitcher manages when he doesn’t have his best stuff, when his fastball doesn’t ride or his curveball doesn’t bite or his slider doesn’t knife. Excellence isn’t what a pitcher does with his best stuff on his best day but how he manages with his mediocre stuff on an off day. A quibble for an otherwise lovely book.

“Smart Baseball” and “Off Speed” are excellent guides to appreciating the game’s nuance.

Smart Baseball
The Story Behind the Old Stats That Are Ruining the Game, the New Ones That Are Running It, and the Right Way to Think About Baseball

By Keith Law

Morrow.

291 pp. $27.99

Off Speed
Baseball, Pitching, and the Art of Deception

By Terry McDermott

Pantheon.

191 pp. $23.95