Its hard to guess actually.. i never know about how big the size kb on each block lol.
Anyway i wanna try but can someone tell me what is average kb of each block
As HardForkComing mentioned, you can use our Block Data tab to see the average block size.
Or use any other block explorer like blockchain.info and to answer the previous question, I have deposited, played and have won on this site also, but in my view it needs more active marketing campaigns because when I visited there was serious lack of players and you need atleast 2 to play a round and it's quite frustrating when you pick the correct size, which is the closest to the block size and you win but then you realize there was no one else in the round.