How many of his chickens will come home to roost?

In the opinion business you must have year-end opinions on what sort of year it was for everybody from the Washington Redskins to the president. For the Redskins, it's easy (10-6, no playoffs). For Ronald Reagan, it's harder. An uncommonly large number of chickens hatched with great fanfare in 1985 will be coming home to roost in 1986.

Some have to do mostly with domestic issues and politics. But some have to do with foreign-policy challenges set in train last year. All will affect the president's standing and his fortunes abroad as well as at home by the end of the new year, and more conclusively than the unfinished business and unfilled expectations that made up so much of the record in the year we have just ushered out. Ronald Reagan's 1986, in a real sense, will be the proof of his 1985.

By way of illustration, start with Gramm-Rudman, a supposed triumph of sorts for Reagan fiscal philosophy. But what this budget-balancing law does is simply to decide to put strict limits on deficits. The really hard decisions on spending come this year, which means that the president must either prevail on cutting domestic programs, renege on his promise not to raise taxes, or suffer serious inroads in defense. An arrested defense buildup is not the bargaining chip he wants on the table at the Geneva arms-control talks.

Still less is that the posture he wants to present to Mikhail Gorbachev when the two renew their acquaintanceship at this year's second summit -- the only real piece of substance to come out of last year's first encounter. Then, Reagan was applauded by his followers for hanging tough on his cherished Strategic Defense Initiative against Gorbachev's seeming determination to stop it in its tracks.

Both men know they are talking for public effect and to no practical purpose, which may be acceptable in a get-acquainted meeting. But now that they're acquainted, more will be expected than "free and frank" fireside chats, defining differences, pledging devotion to peace.

It will no longer be enough for Reagan to say that Star Wars is not on the table when both we and the Soviets know that it is -- and it isn't. That is to say that research and development up to a certain point are not negotiable because they are not verifiable. But advanced development, testing and ultimate deployment are verifiable and will have to be addressed in any comprehensive arms-control negotiating.

Reagan is going to be under especially intense election-year pressures at home, and the usual pressures from allies in Europe, to have something to show in the way of arms control this year. This means getting down to the nuts and bolts of SDI. That means the president can no longer put off the hard business of whipping his own administration into line behind a concerted arms- control strategy.

Last year, the president scored points in some quarters with new emphasis on regional conflicts in Afghanistan, Ethiopia, Angola, Nicaragua and Cambodia. He would support "freedom fighters" in those places in pursuit of negotiated settlements in collaboration with the Soviets. Expectations thus raised could be easily dashed by Soviet intransigence if not by adverse turns in the course of those conflicts, irrespective of U.S. support.

Some see signs that the Soviets might accommodate the president in Afghanistan, for their own reasons. But the regional conflict in the Middle East is one where the United States does not want the Soviets involved. The spirit of Geneva, thus, is hardly improved by new Soviet arms shipments to Libya right when the United States is fingering the Libyans for the terrorist attacks in Rome and Vienna that ushered in the new year.

Last year Reagan gave a little substance to his tough counter-terrorism talk when presented with the chance to capture the hijackers of the Achille Lauro in mid-air. That will be a hard act to follow, the more so since terrorism will almost certainly put the Reagan administration's stated resolve to harder tests in the new year.

If 1985 was not quite the Year of the Lame Duck that the Democrats hoped for, this year could be if the congressional elections produce Democratic gains and perhaps even a Democratic Senate. At the least, it shapes up as the Year of the Chicken -- coming home to roost.