As of today there are 2 solo pools that I know of .

You did not say why you interested in solo mining? Mind to elaborate on your question, for us to give a better answer.

He kind of did explain it, but the supporting math is a bit fuzzy.

Let's assume that you have 1TH/s. Should you point that to a pool, or solo mine? (In solo mining, I'm also going to include the solo mining pools - which I agree is an oxymoron). For this example, there is no merged mining, no transaction fees, nothing but a straight up 25

BTC block reward and we're living in a perfect world where you get exactly your expected earnings every day, blocks take exactly 10 minutes to solve, your rig is 1W/1GH/s and electricity costs $0.10 per kWh, and finally, BTC is $650.

OK. At current difficulty, that 1TH/s expects to earn 0.029

BTC a day, which is $18.85. Power is going to cost you $2.40. Therefore, your daily earnings are $16.45. The same math that tells us our expected daily earnings, also gives us how long that 1TH/s will take to solo mine a block: about 2 years, 131 days.

This is where most people stop and say, "Way better to mine in a pool! I'm not waiting over 2 years!". Here's the fuzzy bit: just because you can "expect" to find a block in that time, does not mean that it "will" take that time. See, each and every single little hash your miners produce has EXACTLY the same chance of solving that block as the hash before it, and the hash after it. In other words, you can just as easily solve 10 blocks in a row as never solving a single block.

I'll give you a concrete example. On April 26th, I found a block with one of my S1s that had only been mining for about 3 weeks. Was I mining solo? No, I was on p2pool. Sure would have been nice, though

Anyway, back to our story. Remember that I stated each and every hash produced by your miner has the potential to solve that block. In a day, there are 144 blocks found. This means I've got 144 chances. Are you a gambler? Are you going to risk $16.45 at the chance for $16250? That $16.45 buys you 144 chances at hitting the jackpot. You have the possibility of hitting all 144 times, too. Just because you solved the last block doesn't disqualify you. So... are you willing to risk that $16.45 at the chance for $2,340,000?

Now, before you all go tearing off and pointing your miners at some solo pool with delusions of becoming millionaires in a day, realize that you have competition. Everyone other miner on the planet is trying to solve those same blocks. Your 1TH/s represents a pretty tiny portion of the total network (currently at 147,000TH/s). Since we have established that every single hash has the same chance to solve the block, this means that 0.000680272109% of the chances belong to you. Or, to put it another way, you've got about a 1 in 1667 shot of solving a block.

Back to the question: are you a gambler?