Ill explain this for ya some.. i have been experimenting with it and even PM'd Crackfoo about it and this is how Nemo auto miner works.. it is a list of algo's YOU ARE GIVING PERMISSION to be mined based on "profitability". Yes typically this miner is mining the most profitable algo throughout the day, but sometimes this is not the case... so how the profit switching works is it connect to the zpool or mph servers, THEY are the ones that determine what algo to mine for you based on the pass list line with your hashrates....so all the decision on which algo is on the pool side of things, you have no control except to turn off the ones you dont want to mine...

So the pool servers get your list, they compare it and there is a list of priorities from there...

1st: if any algo is on the verge of not having enough mining power to stay profitable to the pool and you have it listed as an option to be mined, it will place you on that algo randomly at times if there is not enough miners directly mining it or the pool will temp disable those coins if they are just not profitable enough for anyone to mine them... but if you do get stuck on those random algo's it will switch you as soon as more miners jump on board...

2nd: this is the most common way it determines to mine something.. if your list states xyz is the best profitable algo, it will determine if there is to many miners mining it based on difficulty level being raised as the pool hashrates increases... once the hashrates for the pool exceed a limit the profitability for the pool decreases some.. it will send you to the 2nd highest profitable algo to mine for a bried moment...this is why you see something that appears "most profitable' based on the mBTC/day earnings numbers, but your not mining it for short periods of time... the server priorities miners wallets with more hashrate vs the little guy...

3rd: From time to time the servers will see a high demand for certain coins because the amount of trading volume happen is asking for help from the mining pools to process the traffic in regards of "proof of work", when these periods occur profit is peaked for a short moment even tho the price of the coin didnt actually change in value.. just to many transactions on the network needing processed, so bonus was given out to catch up the network... this is why you see stable coin profit graphs with random spikes for a few minutes with no change in the actual value under pool status...

All above info was shared to me via a collection of others explaining it to me.. what i do personally is check the profit rates daily, i normally find the same 3 are the top 3 for me rigs.. so i leave it.. but i remove all the rest to prevent the constant switching from happening.. my profits increased as i dropped to only have 3, because many times a block of data was sent to me to process and i would mine maybe 1 or 2 lines of it and get accepted from the servers, but if the entire block of data given is not processed completely from start to finish when you switch you loose all earnings on that incomplete block, when the immature's do confirmation on those blocks you mined, it see's them as incomplete blocks and rejects them in your earnings.. so every time you switch algo's your tossing small earnings out for not completing them

please dont ask me to explain anymore than what i just posted, i am not the original info that this all came from, im just passing on a bunch of info explained to me via various people condensed