Table:
text: Dennis Siver
Mixed martial arts record
Mixed martial arts record
Res_ Record Opponent Method_ Round Time_ Location_
Win 16–7 Spencer Fisher Decision (unanimous) 3 5:00 Las Vegas, Nevada , United States
Loss 15–7 Ross Pearson Decision (unanimous) 3 5:00 Charlotte, North Carolina , United States
Win 15–6 Paul Kelly TKO (spinning back kick and punches) 2 2:53 Manchester , England
Win 14–6 Dale Hartt Submission (rear-naked choke) 1 3:23 Cologne , Germany
Win 13–6 Nate Mohr TKO (spinning back kick and punches) 3 3:27 Dublin , Ireland
Win 12–6 Chas Jacquier Submission (guillotine choke) 1 4:21 Darmstadt , Germany
Loss 11–6 Melvin Guillard TKO (punches) 1 0:36 Las Vegas, Nevada , United States
Loss 11–5 Gray Maynard Decision (unanimous) 3 5:00 Las Vegas, Nevada , United States

Question: What was the solution method for Dennis Siver vs Dale Hartt fight?