Newbie question

the number below the odds is how many people are watching you nervously decide wether to back unders or lay it. they are all laughing at you.

Joined 24.7.07

Yes, it's how much money there is available for you to match. So if you're backing, the money you see is from people doing the opposite (laying) and vice versa.

Ignoring the seethers, even if this is a level chances are there might be newbies reading the thread anyway wondering the same thing so here's a quick explanation.

Under each odds is the amount available. You can put up a price you want with the amount you want at any odds, you don't have to take the odds offered. You will see the money you're offering on the other side. So if ask to back at 1.5 with £10 you'll see a 1.5 with £5 under it appear. (assuming the current odds are shorter, if there is currently better offered then betfair will match you at the best price you can get).

In some markets such as a two horse race, betfair will convert your back ask into an equivalent back offer on the other side too.

You can see the market coverage, if this is above 100.5% or there about on the back side, it's worth asking for a bet instead of taking what is given, as it means the market isn't fully efficient. When this happens, it means there is an implied spread between what is currently being offered on each side. It means if you backed all options, you could arb it for a guaranteed (small) loss. If you put up offers and wait to be matched you can often construct it so as to guarentee a small profit. (But if nothing else it just means you get a better price).

Market depth is often important and worth watching because it shows the way the odds are more likely to move (given no other events). For example if the market shows 1.49 £10000 1.50 £10, then everyone is looking to lay at 1.49 yet few are looking to back at 1.50! Chances are the market will soon show 1.50/1.51, if someone puts in a £20 lay then this is what would happen, the 1.49 would still be there but deeper in the market and no longer the best price offered, the 1.50 offer would be part matched and now show 1.50 on the "blue side" and the rest of 1.51 offers would move into the best red.

Don't rely on this of course, markets are the price they are for a reason, you should avoid ever trying to second guess market movements, the best indicator of the future price is the current price, otherwise the price would move to adjust. (Markets are forward looking). Also, if you lay at 1.50 because you think the market will move to 1.50/1.51 then you won't actually profit unless you can get a 1.51 back matched (which should happen if you wait long enough in a market showing 1.50/1.51).

A good long term strategy in betfair is "always offer, never take". By taking odds you are giving others a better deal than they could currently take, by waiting to get matched, whoever matches you gives YOU a better price than you could have got through matching.

Be careful to cancel quickly in the event of new information of course, this is mostly relevant for pre-match odds.

If you're a small/medium time (under £100 staking) then market depth shouldn't worry you too much, it only really affects 'lumpy' who sticks down £10,000 a time at a price. Mispricing here can mean a 4 or 5 "tick" drift to the price they get. I saw a T20 game where someone mis typed a 1.04 lay for 1.4, with £10,000 that meant he single handedly pushed the price to that point! (There was about £2k waiting to get matched at 1.05/1.06 and a few hundred at the other odds up to 1.4, then a whole load got dumped at 1.4). Must have cost them a fortune!