Even in defeat, John Elway was one hard-to-corral Bronco

He wasn't on the winning side, but the kid who made Super Bowl XXI worth watching, even after the New York Giants punched out a two-touchdown third-quarter lead, was John Elway. The exciting young Denver quarterback had a first half that doesn't usually happen in anything as important as the playoffs or the Super Bowl. In just 30 minutes, he completed 13 of 20 passes for 187 yards and one touchdown, and he earned every bit of it.

He simply stood back, calmly surveyed the entire field, and then hit his receivers on the numbers. Then late in the first quarter he caught the Giants looking for a pass and ran a quarterback draw right up the middle for a 4-yard touchdown.

Elway's high point, though, probably came early in the second period on a drive that put Denver on New York's 1-yard line. On successive third-down plays, he threw a 54-yard completion to Vance Johnson, a 6-yarder to Orson Mobley, and a 7-yarder to Steve Sewell. The fact the Broncos failed to score may have been the fault of some questionable decisions, relayed from the bench, to attempt to bang it in on the ground against a defense that eats ball carriers.

One reason the Giants began to contain Elway better in the second half (when he was 9 for 17 with one TD toss), was that they finally noticed how often he had been throwing to his running backs. Consequently, they went almost exclusively to zone coverage, which allowed them to get more defenders to quickly converge on the intended receiver.

Explained Elway: ``In the first half, the Giants gambled a lot on defense and we were able to take advantage of that. They were mixing zone with a lot of man-to-man coverage, and if you're a quarterback it's considerably easier to beat one defensive man who isn't getting any extra help. But in the second half, the Giants seldom got out of their zone, and we were so committed to staying with what had worked so well before that we probably stayed with it too long.''

Elway is the chief reason why Denver should be in the race for the Super Bowl for years to come. If the Broncos could somehow come up with an established runner between now and next season, opposing teams would be forced to gear their defenses for more than just stopping Elway and the Denver passing attack. Giants waited 23 years

The last time the Giants played in a championship game was 1963, and the last time they won a National Football League title was 1956. This was a franchise that had a lot of tradition going for it, having been established in 1925, but during the past two decades the club couldn't seem to find players who fit together or a head coach who knew what it took to win.

A rift at the organization's top rung didn't help, either. The two men who own the Giants (Wellington Mara and his newphew, Tim, who inherited stock from his father) haven't spoken to each other for eight years. The roots of the problem involve who has the last word in team decisions.