Regression analyses have been used for over 2 decades to develop useful statistical relationships between estimates of fish catch and various members of a set of abiotic and biotic variables. In this study a number of conceptual and data refinements have been attempted with respect to certain lake data. More complete data are now available than was the case with earlier authors such as D. S. Rawson and R. A. Ryder. Rather than use average long-term catch, approximate estimates of maximum sustainable yield (MSY) were derived. The MSY of all species combined, Ct, was estimated as well as the MSY of a set of preferred taxa, Cs, comprising lake trout (Salvelinus namaycush) plus lake whitefish (Coregonus clupeaformis) plus walleye (Stizostedion vitreum) plus sauger (S. canadense). The most significant predictive relationships included only one independent variable, average dry weight of bottom fauna standing crop. which explained 83% of the variation of Ctper unit water area in a semilog relationship, and 80% of the variation of Ctper unit area and Csper unit area in log-log relationships. The best relationships incorporating solely abiotic variables included mean depth and total dissolved solids concentration as the only significant independent variables, and explained less than 70% of the variation. Other factors analyzed included the annual cumulative degree days above 5.6 C, the presence or absence of thermal stratification, and the average dry weight of net plankton standing crop.