The problem of compact, fully efficient representation of multilocus data has not yet been solved. Lod scores can be used to map multilocus data, but because of certain statistical problems, this method loses some information. However, simulation studies show that for distances less than 10 or 20 cMo, where there is little danger of huge overestimates of distance, the lod score method yields estimators just as good as maximum likelihood (ML). Since short distances are the most important, the lod method is quite efficient. Its main drawback is misrepresentation of the likelihood under wrong gene orders. This problem can be ameliorated with a single multipoint calculation under each order. Thus, representation of multipoint data with lod scores can be very practical.