Time to find a block in seconds = (2^32 * difficulty) / (your_hashrate_in_Mh/s * 1e6)
That is for most coins, but not all. Anyway, you can get the difficulty by using getmininginfo in the wallet, under debug.
So for example, if your hashrate is 1000 Mh/s and the coin's difficulty is 838.9, you'll end up with 3600 seconds (e.g. 1 hour) between finding blocks on average. The last point is very important because it ignores variance (luck) so in reality you could go even days without finding a block or you could end up finding dozens of blocks under an hour.
So it's not about jackpot, it's just simple variance.
Very enlighting. Is that how the "Go solo ?" column is printed here : http://www.cryptocoinsinfo.com (ex. @1000H/s, Karbowanec KRB, 5.9 days, expected time per block solved)
There may be a more complete listing as well but where, whattomine.com does not output this ?
I'm not familiar with that site but some sites calculate the chances of finding a block based on how long it (should) take for the whole network to find a block (e.g. 10 min for Bitcoin, 2,5 minutes for Litecoin, etc). That basically means they're working from historical averages ignoring the actual difficulty of finding blocks and since difficulty can swing a lot, it will always be the most accurate metric (the complexity of the job your miner has to solve to find a block is basically multiplied by the difficulty).