Complex sentence: The start of the race was delayed for more than twenty minutes as the starter struggled to control the runners leading the favourite, Kennymore, the winner of the 2000 Guineas tp become increasingly fractious, lashing out with his hooves and attempting to attack other horses.
Split into simpler sentences: The start of the race was delayed for more than twenty minutes as the starter struggled to control the runners. The favourite, Kennymore, the winner of the 2000 Guineas became increasingly fractious, lashing out with his hooves and attempting to attack other horses.