The forces from Princeton invade today, and if the Crimson-Tiger confrontations of the last two years are any indication, today's Harvard Stadium battle will be a rough-'em'up, knock-'em-down affair.

Princeton stands at 1-4, while Harvard is 3-2 and--as the bumper sticker says--"IN MOTION." But both history and a realistic look at the respective football battalions indicate that today's game will be anything but one-sided.

Relive 1975 for one second. With the Crimson trailing 24-0 early in the fourth quarter, Harvard rode the golden arm of third-string quarterback Tim Davenport to a near-miracle before Davenport bobbled a snap from center with four minutes left. Princeton 24, Harvard 20.

One year later, Crimson drop end Bob Baggott returned the insult, jarring the ball loose from Tiger QB Kirby Lockhart and recovering the fumble with Princeton driving for the touchdown five minutes from the final gun. Harvard 20, Princeton 14.

Move up to 1977, and find Harvard--minus the injured Davenport--looking less than strong in its opening contests, and Princeton playing well in its early games but practically giving away three decisions by a total of ten points.

Winning Helps

Enter the fifth week of the season and, bang-bang, the Crimson--by virtue of the Dartmouth win--has emerged as a crunching football machine.

Except for the unknown status of injured defensive linemen Charley Kaye, Steve Kaseta and Russ Savage, all the signs bode well for Restic's troops. The word around Soldier's Field is that even practice went exceedingly well this week.

But the Tiger army represents more than a bunch of lowly challengers. Coach Bob Casciola's mean 5-2 defense, led by linebackers Andy Hvidston and Bob Ehrlich, and middle guard Pete Funke, limited its opponents to 41 points in the first four games, before relinquishing 31 digits to a powerhouse Colgate squad last week.

On offense, the Tigers have a solid front wall anchored by center Andy Stephens. The backfield combination of speedy tailback Bobby Isom and fullback Gary Larson may be the best in the league. Only the passing game of quarterback Lockhart--injured versus Colgate but apparently ready--is suspect.

Restic, clearly, is concerned. "They keep you honest, running inside out of the I," the stone-faced coach said yesterday, "then they go outside with Isom. We just can't let them control the ball against us."

The game just may boil down to ball control. The battle will take place in the trenches, man against man, line against line. If the historical precedents of '75 and '76 hold true, ball control--or the lack of it--will indeed play a major role.

Restic is not too concerned that late fumbles will turn the tide in today's skirmish, though.

"If it turns that way and we're out front in the end," he said, "I won't be too unhappy."