When are wagers co-mingled?
 

Saw a horse yesterday at DMR drop from 15 to 1 with a couple of minutes to post to 10 to 1 in the gate and then to 6/1 after the race began. Is this because the off-track sites dump the money late or are wagers co-mingled as soon as they are bet. For instance if you bet $2 win on TwinSpires would that money instantly go into the pool for the track you bet.

As I understand it, the bets go to a hub in Oregon & then they enter the bets into the pools at their leisure. This is an interesting point. If I'm in NYC & place a bet on a race in Ohio, Why should it take more than a minute to hit the pool in the Ohio track? The NYC betting site is not delivering the money physically, they are just sending an electronic signal. As a test I just placed a $100 show bet on the #6 at BTP & it took 1 minute & 31 seconds to show in their pools. If that is the standard & I place a bet on a 5 furlong race at 0 minutes to post, the race could be over before the bet is reflected in their pools.

There are several different tote systems involved for racing, and the path your bet takes getting to a point where it's reflected in the track's pools displayed can vary by quite a bit. But suffice it to say, your $2 bet on Twinspires will never "instantly" get into the track's pool. There will always be some lag, though you may not notice if you time the wager with the "refreshes" just right.

If you make a bet with 10 minutes to post at TS, chances are within a couple of minutes that bet will show up in the pools on track, since it's been my experience that TS transmits the wagers on an ongoing basis, and it appears to be at least once every minute. I don't know if that's true for all ADWs (probably not), though of course they're all locked out simultaneously when the race starts (or so we are told). If you make your wager within a minute to post, then it may very well get "lost in the shuffle" of the late avalanche of money. If you refresh the pools on TS though, you'll note that within 20 seconds or so after the start of the race, the pool's final numbers are displayed, at most tracks. This has improved somewhat over the tote's lag from 20 years ago, IMHO.

There has been some discussions around making the refreshes more frequent (say every 20 seconds), so that bettors aren't "surprised" at final odds as often. But because some of the largest bettors wait until the last 20 seconds or so to bet, you're always going to see the occasional "steam" horse whose odds drop late.

So if you are watching live racing at Louisiana Downs and bet $1000 to show on a horse there and $1000 to show on a horse running at Thistledown are they both going to hit there pools at the same time. In other words does a bet placed live at the track have the same delay as a bet placed for another track.
Also, I remember a few years ago in Vegas race books there was a sign that read Exacta payouts limited to $200 - what happened to the rest of the money or were they not co-mingled at that time.

We were supposed to have near instantaneous bet cycles by now, but either laziness, ineptness, or incompetence, probably all three, have delayed this ad infinitum.

To answer your second question first, Vegas used to book their own bets, all profits or losses into or out of house funds. For their own protection they would limit payouts. I remember when they would limit win payouts to 15/1. In short, they were not co-mingled with the paramutual pool.

As far as your first question, in theory both bets should hit at the same time. In real life it usually doesn't look to be the case.

Pools are transmitted from guest to host at 30 second intervals for most tracks in North America. This is down from 60 seconds which was the norm a few years ago.

The tote companies are testing shorter intervals. so some tracks are transmitting more quickly than that. The goal seems to be to get to 10 seconds for win pools under the current ITSP protocol.
No, the on-track bet on Louisiana Downs would be in its pools before the Thistledown bet made it to Cleveland, as the Thistledown bet would not be transmitted until the next regular cycle of the pools.