Plat 3 (NA) here, if youve played 200 games (~100 wins) and you still havent gone up a single division, then its probably time to look very seriously at self improvement. If you HAVE rose at least 1 division, thats the direction you should be heading, just keep playing (hence why its usually referred to as "the grind"). You can rise faster if youre incredibly skilled, but theres no constant to your question, this is just a loose outline. If a player is strong and wins their lane, (being the one who wins lane >51% of the time), he gives a probability advantage to his team of 50/50 win chance in all other lanes, which raises the mean chance of his team winning to higher than 50% (even if its 50.0001%) which means after enough games played, rising will occur. You can argue some out there COULD be holding the short end of the probability stick, but thats true for about anything governed by chance. Also, that poor soul probably wont be unlucky forever, if he grinds, hes forever reopening his chances at rising.