if u look at the battle data charts for all the captains, it's goes like this.
1. Yamamoto/Aizen- they're tied as they both have 560/600
2. Unohana- 540/600
3. Shunsui- 530/600
4. Byakuya-510/600
5. Toshiro-500/600
6. Ukitake-490/600
7. Gin-480/600
8. Sajin-470/600
9. Soifon-460/600
10.Tosen-460/600
11.Mayuri-430/600
12.Kenpachi-390/600

shorty35565 you are so wrong aizen stated long ago in the manga that he could never beat yamamoto in a straight fight, check your facts. Manga trumps all.

data charts dont gauge strength in the world of bleach shunsui and ukitake are far stronger than byakuya and toshiro and gin is stronger than toshiro kenpachi is stronger then mayuri soi fon sajin dont pay attention to those charts just read the manga and string the facts together