Complex sentence: Shin estimated for Sena's Final Play against him that he was able to run a 40-yard dash in 4.1 seconds by using Shin's arm as a propellant.
Split into simpler sentences: Shin estimated for Sena's Final Play against him that he was able to run a 40-yard dash in 4.1 seconds. He achieved this by using Shin's arm as a propellant.