Complex sentence: Rosinsky was a decorated amateur, winning the New York Golden Gloves four times, as well as the 2005 United States Amateur Championship at light heavyweight, before successfully turning pro in 2008 with a first-round TKO over Valetine Fortanelly.
Split into simpler sentences: Rosinsky was a decorated amateur, winning the New York Golden Gloves four times, as well as the 2005 United States Amateur Championship at light heavyweight. He successfully turned pro in 2008 with a first-round TKO over Valetine Fortanelly.