Lou Gehrig. His last full year was in 1938 and he was 35. He batted .295 with 29 HR and 114 RBI. These numbers were awful for him and the press couldn't believe how poorly he was playing not realizing he put up these numbers while having ALS. He died in 1941. Who knows what his final career numbers would have been if he got to finish his career on his terms. I have read two books on Gehrig, one about his career and the other chronicling his remarkable 1938 season. When he entered the doctors office at the Mayo Clinic the doctor knew immediately his diagnosis. Still no cure today.