After winning the NL East in 2012, the Washington Nationals are coming into the year with a cacophony of hype. But Thomas Boswell says focusing on this year’s potential is missing the point. (Brad Horn/The Washington Post)

In Florida, Bryce Harper is hitting .474. It’s only 19 at-bats, but everything he hits is a missile. So once again, we ask, “How good will Harper be and how soon?” The most likely answer may surprise you: amazingly good and very soon, probably this season.

With a huge winter storm fixing Washington right in its crosshairs, let’s think warm thoughts. Let’s imagine what Harper, who had the best overall season of any teenager in big league history last year, might do if he has, say, one of the best 20 seasons of any 20-year-old.

At that age, Ted Williams drove in 145 runs, and Mel Ott 151. Alex Rodriguez, Ty Cobb and Al Kaline hit .358, .350 and .340, respectively, and all won the batting title. That may have been A-Rod’s best season ever. Frank Robinson hit 38 homers, and Tony Conigliaro led the American League with 32.

Vada Pinson and Mike Trout scored 131 and 129 runs. Mickey Mantle finished third in the MVP voting. Pudge Rodriguez and Johnny Bench were all-stars and won Gold Gloves. Miguel Cabrera’s cleanup slugging (12 postseason RBI) helped the Marlins to a world title. Jimmie Foxx, Arky Vaughan, Rogers Hornsby, Orlando Cepeda and Ken Griffey Jr. hit .328, .318, .313, .312 and .300, respectively.

And at 20, Babe Ruth went 18-8 with a 2.44 ERA as a southpaw pitcher for the world champion Red Sox and hit .315 when they let him bat.

Before you say, “Harper can’t possibly do anything like that,” just look at his numbers for the last 41 games of last season. He hit .327 with 12 homers, 37 runs and an on-base-plus-slugging percentage of 1.045. How good is 1.045? It is exactly the OPS that both A-Rod and Teddy Ballgame had at 20. Harper most likely won’t be that good. But a year ago, who thought he would be the best teenager ever, edging out Ott (who hit 42 homers at 20)?

Regardless of generation, when great players appear in the big leagues as regulars at a young age, they tend to blossom very quickly, and some of their very best years arrive at 20 or 21. Yes, others, such as Robin Yount, get to the big leagues early but need years to become top hitters. And plenty of the best players in history are invisible at 20 or even at 24.

There’s no rule, but there certainly is a pattern not many seem to grasp.

FanGraphs offers four sets of Sabermetric “projections” for every player this season, based on age, minor league numbers and especially previous big-league totals. So, naturally, because they are looking at a wide range of talent levels, they get modest answers for Harper’s 2013 production.

All four have nearly identical predictions. Bill James projects Harper will play 154 games and hit .272 with 65 RBI. The average of the four gurus is 153 games and a .274 average with 24 homers, 90 runs and 73 RBI.

Come on, man, give me a break. Last season, Harper spent the Nationals’ first 20 games in the minors and still hit .270 with 22 homers and 98 runs scored after his promotion. If healthy, Harper might pass those “projection” numbers in August.

Harper and Manager Davey Johnson, who has installed Harper as his No. 3 hitter, have a better sense of the lay of the land. As soon as he got to spring training, the now-230-pound Harper said, “There are [personal] goals in my head, but I’m not going to share them. People will think I’m crazy.”

“You know what’s pushing Harper,” said Johnson, who was third for rookie of the year in 1966, then improved the next season. “Mike Trout.”

Trout’s magnificent 2012 season has been mislabeled as “one of the greatest of all time.” It isn’t. He doesn’t even beat A-Rod, Ott or Williams for best season at 20. Most of the best hitters had a half-dozen seasons that were equal to or better than Trout. (We’ll argue later.)

Dazzling as Trout was, his basic achievements at bat — .963 OPS, 30 homers, 129 runs ands 83 RBI — are not unthinkable goals for Harper.

Most projections for Harper put him into the wrong category: all ballplayers. Compared to everybody, anyone’s chances of being superb look dim. But what if we compare Harper to a more accurate peer group: No. 1 overall draft picks taken out of high school that played power positions?

Since the 1977 draft, here is the list of just successes: Harold Baines, Darryl Strawberry, Griffey, Chipper Jones, A-Rod, Josh Hamilton, Adrian Gonzalez and Joe Mauer (three batting titles by 27). Justin Upton’s grade is “incomplete,” but he is a cautionary note for Harper fans. At 20, he was as good a hitter (per at-bat) as Harper at 19, but six years later, he isn’t any better.

When these No. 1 overall picks became established in the majors, they almost always got better dramatically. The younger they arrived, the more they improved. Who flopped? Only Al Chambers, Shawn Abner and mediocre Delmon Young, who hit .288 as a rookie at 21 but never got better.

If Harper remains much the same hitter as he was in ’12, then it won’t mean he has hit his ceiling. Plenty of exceptional hitters didn’t erupt until their mid-20s. But a Harper who regresses or stays the same is unlikely.

The key is probably Harper’s ability to avoid or minimize long slumps. His scalding final 41 games of last year were immediately preceded by a 41-game slump in which he hit .198. Scary symmetry? Streaks and chilly spells never go away. But the hot periods need to get longer, the cold ones shorter.

Very few future greats have had excellent seasons at 19. That made Harper’s rookie year stand out even though his production, if he’d been 29, would have been just a very good year. Now, it’s different. Players have won homer, RBI and batting titles at 20. So the bar for Harper will rise. That’s an opportunity and a weight.

But it’s not unfair. If the late Pinson, an excellent but not historic player, could debut at 19 and have 205 hits, 84 RBI and a .316 average at 20, why is something similar unreasonable for Harper?

There is far more precedent for a remarkable season at 20 than as a teen. Expecting such a feat is too much. But being aware of history just whets our appetite. The possibility of an outlandish season is far from outlandish.

For previous columns by Thomas Boswell, visit