Table:
text: Federer–Nadal rivalry
Singles
Singles
Year_ Tournament Surface Round Winner Score Length_H_MM Sets_ Federer Nadal
2007 Tennis Masters Cup Hard (i) Semi-final Federer 6–4, 6–1 0:59 2/3 6 8
2008 Monte Carlo Clay Final Nadal 7–5, 7–5 1:43 2/3 6 9
2008 Hamburg Clay Final Nadal 7–5, 6–7 (3–7) , 6–3 2:52 3/3 6 10
2008 Roland Garros Clay Final Nadal 6–1, 6–3, 6–0 1:48 3/5 6 11
2008 Wimbledon Grass Final Nadal 6–4, 6–4, 6–7 (5–7) , 6–7 (8–10) , 9–7 4:48 5/5 6 12
2009 Australian Open Hard Final Nadal 7–5, 3–6, 7–6 (7–3) , 3–6, 6–2 4:23 5/5 6 13
2009 Madrid Clay Final Federer 6–4, 6–4 1:26 2/3 7 13
2010 Madrid Clay Final Nadal 6–4, 7–6 (7–5) 2:10 2/3 7 14

text: Federer–Nadal rivalry
Singles
Singles
Year_ Tournament Surface Round Winner Score Length_H_MM Sets_ Federer Nadal
2006 Roland Garros Clay Final Nadal 1–6, 6–1, 6–4, 7–6 (7–4) 3:02 4/5 1 6
2006 Wimbledon Grass Final Federer 6–0, 7–6 (7–5) , 6–7 (2–7) , 6–3 2:58 4/5 2 6
2006 Tennis Masters Cup Hard (i) Semi-final Federer 6–4, 7–5 1:53 2/3 3 6
2007 Monte Carlo Clay Final Nadal 6–4, 6–4 1:35 2/3 3 7
2007 Hamburg Clay Final Federer 2–6, 6–2, 6–0 1:55 3/3 4 7
2007 Roland Garros Clay Final Nadal 6–3, 4–6, 6–3, 6–4 3:10 4/5 4 8
2007 Wimbledon Grass Final Federer 7–6 (9–7) , 4–6, 7–6 (7–3) , 2–6, 6–2 3:45 5/5 5 8

Question: What were the sets when Federer had 6 and a Nadal of 13 for the singles of the Federer-Nadal rivalry?