The Twins plan to retire soon to be hall of famer Bert Blyleven this season.  The Twins will retire Blyleven's number 28 July 16 against Texas.  He will become the 6th Twins player to have his number retired.  The others are Harmon Killebrew, Rod Carew, Tony Oliva, Kent Hrbek and Kirby Puckett.  Twinsfest begins today and goes through Sunday at the National Sports Center in Blaine.  More than 60 current, former and future Twins will be available to meet and greet and sign autographs during the 3-day event.  The event was moved to Blaine because of the Metrodome rood collapse.