Complex sentence: The Television Trophy was hosted at the track for the third time in 1997 following the previous staging in 1979 & 1988 and in 1999 the Blue Riband competition was brought to the track following the demise of Wembley with the Grand National switching to sister track Wimbledon Stadium.
Split into simpler sentences: The Television Trophy was hosted at the track for the third time in 1997 following the previous staging in 1979 & 1988 and in 1999 the Blue Riband competition was brought to the track after the demise of Wembley. The arrival of the Blue Riband resulted in the Grand National switching to sister track Wimbledon Stadium.