Michalczewski hangs up gloves   Dariusz Michalczewski, who simultaneously held three of the four major light heavyweight championships in 1997 and also won a world cruiserweight title, announced his retirement from professional boxing at a press conference in Hamburg, Germany. Michalczewski's reign as WBO champion lasted nine years and the IBF and WBA titles were unjustly stripped from him. According to the website of his promoter, Universum, Michalczewski will start a boxing management company. Born in Poland but based in Germany for most of his career, the 37-year old Michalczewski finishes with a record of 48-2, with his only losses coming in his last two bouts.  His list of victories includes several boxers who held world titles at one time or another: Virgil Hill, Graciano Rocchigianni, Montell Griffin, Nestor Giovannini and Leeonzer Barber. In America at least, Michalczewski's legacy will be that of a very good boxer who always gave his best in the ring, but who avoided the defining challenge of his career, a bout against Roy Jones, Jr.  In fairness to Michalczewski, Jones must also shoulder some of the blame, because neither man was willing to venture outside of their own country to wage a true world light heavyweight championship contest.   -Scott Shaffer