Complex sentence: Glenn Ordway, the main host of the show, performed radio announcements with Boston Celtics announcer Johnny Most for 13 years; after Most's retirement, Glenn was paired with former Celtic Jerry Sichting.
Split into simpler sentences: Glenn Ordway, the host of the show, performed radio announcing duties with Boston Celtics announcer Johnny Most for 13 years. After Most's retirement, Glenn was paired with former Celtic Jerry Sichting.