Hand reading by process of elimination

Often times you can eliminate hands from a player's range, either by what's on the board, in your hand, or your opponent's actions. This leaves you with a smaller range to put your opponent on, which helps you make better decisions. Here's one hand where I used what was on the board and in my hand to make a bluff:

Seat 1: HERO (BB) ($110.75)
Seat 3: MP ($50)
Seat 5: button ($44.85)

*** HOLE CARDS ***

Dealt to HERO [7s 7d]
MP raises to $1.75
Button calls $1.75
HERO calls $1.25

*** FLOP *** [Qs 2h 9s]

HERO checks
MP bets $3
Button folds
HERO calls $3 (I thought this was a pretty ghey bet and even out of position I thought I could continue in the hand profitably)

*** TURN *** [Qs 2h 9s] [As]

HERO checks
MP bets $6
HERO raises to $18 (OK, here's the interesting part of the hand. This is like THE scare card in the deck and I check-called the flop. If he's even half-way decent, he will be bluffing this card with most of his nothing hands, all of his very good hands, and checking behind only decent made hands that he doesn't want to get blown off, like AT or AJ, maybe with a spade. Now notice - this guy raised from MP, there are three big spades on the board, and I have the 7s in my hand. What other spade hands could he have raised with? KJs certainly. JTs almost certainly. KTs and T8s possible but less likely. Basically, there are somewhere between two and four SPECIFIC hands in his range that just hit that card, mixed in with all his nothing hands that he's now bluffing. The only other hands he could really continue with are sets and AK with the K of spades, both of which he might have checked for fear of the flush. Anyway I decided to raise - which I probably would not have done if the turn were, say, the deuce of spades because then his many Ax of spades hands are still possible - and he instafolded.)
MP folds

Here's one where I had a river decision vs. a donk:

Seat 5: BB ($50.80)
Seat 6: HERO (UTG) ($138.45)

*** HOLE CARDS **
Dealt to HERO [Ts As]
HERO raises to $1.75
BB calls $1.25

** FLOP ** [3s 3d Kc]

BB checks
HERO bets $3
BB calls $3 (Standard so far...I c-bet, he calls, I put him on some middle pocket pair, a weak king, maybe a slowplayed 3.)

*** TURN ** [3s 3d Kc] [Th]
BB checks
HERO bets $6.50 (I'm now ahead most of those pocket pairs, and I usually get little credit in these spots, so I need to value bet thin.)
BB calls $6.50 (No raise here means I'm pretty confident he does not have a 3. He could still have a K. I will probably check behind if the river is a blank.)

*** RIVER ** [3s 3d Kc Th] [2d]
BB bets $18.50 (WTF? This bet definitely surprised me. I would be really surprised if he would lead out big with a K like this. The donk line with a K here is to check-call again. Once we've eliminated a K, what's left? Pocket 2's? He slowplayed 3's until the river? Those hands are just too rare...plus he would have had to call down with 22 or have slowplayed 2 streets with trips, and I'm not willing to give him credit for having done either. His story doesn't really add up, so I'm gonna call.)
HERO calls $18.50

Guesses as to what he had? Like my call? I will personally ship $5 to you on FT if you can nail his hand down. I'll post the answer in the next couple of days....

-BRUECHIPS