What are the clocks shown beneath the game boards?
The game clocks beneath the boards tick between moves. When it's your turn then your clock ticks and when it's your opponent's turn their clock ticks. What it shows is how long the game has been sitting on each player's Game sheet waiting for them to move. The smaller the number the quicker the player has been in responding when it's been their turn.
As an example let's consider a game of yours which might have been running for some time and 96 moves have been made. Your clock says [Clock: 7:23:44]. This means that in the 96 moves that have been made the game was on your Games Sheet for about 7 days, 23 hours and 44 mins. You've responded, on average, after about 2 hours of it being your move. Your opponent's clock shows [Clock: 180:22:50] which means that it's been on their Games Sheet for 180 days, 22 hours and 50 mins. Maybe some days they've made a few moves and maybe at other times they've taken a few days to make one move but on average they've taken a couple of days to make each move.
That's all those clocks do - tell you who's had the game on their Game Sheet for how long, though, of course, that's the amount of time that the other player is waiting for the game to come back to them. A pair of such clocks tells you whether one player is slower than the other and by what ratio. In this example it's about 2 hours to 2 days.
However, you need to be a little bit careful in using the clocks to determine whether someone is a slow player or not. You don't necessarily get an accurate view from a single game, especially if not many moves have been made yet.
As an example say that both you and Bill each log on once a day and usually only get to make one move in each of your games. One might expect both of the clocks to show that 12 hours are taken on average to make moves but that may not be so. If you regularly log on at lunchtime, and Bill logs on at teatime then the game would only ever be on Bill's Game Sheet for a few hours in the afternoon. After Bill moves the game would then be on yours for the evening, the night and the next morning. This timing effect would make it appear that Bill moves quickly and that you are holding the game up. It is therefore a good idea to look at a number of different games against different opponents if you want to get a more accurate idea of how fast a player someone is.