How come there's sometimes .25 in the middle of the table?

[AA suited]

this is at the beginning of a deal.

why is there .25 and where did it come from?

[pudley4]

Playing on a .5/1 table, if someone posts their missed blinds, the .25 SB is "dead" and put directly in the middle.

[benfranklin]

If you are sitting out and the blinds go past you, you can either wait for the BB to get to you again and just put in the BB as usual, or you can post the BB and the SB you missed and play from whatever position you are in (except the button). The SB is "dead" and goes directly into the pot, the BB is your starting bet for that hand, and you can check or raise when the action gets to you.

Then you still have to put in the BB when it comes around to you normally.

[cardcounter0]

It came from the guy who was sitting out, but has now rejoined the game, and had missed the blinds in the meantime.