I've read a few of the responses and nobody seems to have pointed out that SB may well be playing you off Mr. Loose. If Mr. Loose is also Mr. Maniac -- WHAT'S HIS POSTFLOP AGGRO? -- then SB may well assume that his 9 is good and be hoping that his cap would do, well, exactly what it did do.

btw -- you said in a follow-up post that K9 or A9 is an easy decision for SB. I disagree. He may well prefer to c/r versus bet out.