Danny Kaye, like most genuine comedians, is at his best as a scat-back, alone in an open field. As soon as the blockers form in front of him and the routine plays have to be run off, he either loses interest in the game or trips over his won teammates. Mr. Kaye and other producers of "Knock on Wood," while apparently aware of this fact, were too obeisant to the traditions of Plot to take full advantage of it. The result is a picture which is funnier than most, but never so funny as it could have been.

The trouble with the plot is that it is completely ludicrous and yet no one involved in the picture, either actor or writer, seems to consider it anything but deadly serious. In their better efforts the Marx brothers, for example, were ensnared in some of the most tangled creations ever conjured up by ulcer-ridden, psychotic screen-writers; the movies were masterpieces nevertheless because no attempt was made to establishing continuity, plausibility, or any other of the rules of scripting.

In "Knock on Wood," Kaye plays an American ventriloquist who, while touring Europe, becomes the unwitting carrier of a set of horrendously important atomic blueprints. Since not only the original owners of these plans (Our Side), but also two competing sets of Middle European badmen are after the documents, Kaye soon assumes the position of the rabbit in a greyhound race. The epic chases and subtrefuges which result, however, have their edges dulled by limp globs of plot which necessarily precede and follow each comedy sequence.

Even more embarrassing and stultifying, however, is the attempt to give the ventriloquist dimensions as a character by giving him a psychosis which prevents him from marrying the women he falls in love with this boresome idea is not abandoned as soon as the action is underway, but instead is followed through down to the last guilt complex. The audience is shown a sodium amytal treatment, a flashback to the patient's youth ("You see, his father and mother quarrelled..."), the patient falling in love with his beautiful young psycho-analyst, and, as a grand climax, the paient curing the psycho-analyst, of her psychosis.

But when all this clap-trap is out of the way, Kaye rides triumphantly through the rest of the picture, assuming Eton accents, Irish brogues, car salesman mannerisms, and ballet postures with equal facility. It is only too bad that the people responsible for "Knock on Wood" seemed to feel that something inherently funny could be made out of a mother fixation and some stolen atomic secrets.