Distribute loss not matched

Hi
It's probably the Betfair in-play delay.

As you say you can use a lay trigger:
Price: r_ticks(lay_price, 5)  this will lay at 5 ticks higher than best lay price, replace 5 with how many ticks higher you want to lay
OR
Price: best  this will be matched at best available lay price
The formula for the amount for equal profit or loss on all selections is (bm_backp*bm_backa)/lay_price
Use conditions to make sure you are getting a reasonable lay price, for example, no more than 10 ticks spread between best back and lay prices:
and selections trigger expression g_ticks(back_price, lay_price) is equal or less than 10

As another option you could add another trigger to match unmatched lay bets at best available price:
trigger action: match lay unmatched bets
and use similar conditions to above

And another option you can use is the Stop Loss Options in the Settings, for example:
match unmatched bets: If a bet was placed 1.00 mins ago or earlier
in this case your trigger would fire the distribute loss, and if it was unmatched 1 minute later, it would then be matched at the best available price

please use test mode for testing these 

Hi
A Distribute Loss trigger (using ticks or profit%) will use the current lay price, which you are missing because of the in-play delay
the suggestion is a LAY trigger five ticks higher than the current lay price instead of Distribute Loss, so using the same conditions in your example:

Action: Lay
Price: r_ticks(lay_price, 5)
Amount: (bm_backp*bm_backa)/lay_price
conditions:
markets betting code is Over/Under (Soccer) 0.5
and selections trigger expression match_minute is equal or greater than cbt
and selections back matched is greater than 0

if you are using a green-up trigger, you need to add another condition so this does not fire if the green-up has been done:
and trigger <name of your green-up trigger> number of runs is equal to 0  

Hi
I don't think you need to cancel then lay.

Either increase the 5 ticks higher lay price r_ticks(lay_price, 5) to say 10 or 15 ticks: r_ticks(lay_price, 15)

OR

lay at "best" price, this will match it immediately at the best available price:
Action: Lay
Price: best
Amount: (bm_backp*bm_backa)/lay_price
conditions:
markets betting code is Over/Under (Soccer) 0.5
and selections trigger expression match_minute is equal or greater than cbt
and selections back matched is greater than 0

OR

use the Stop Loss settings mentioned earlier

Hi
You can modify the cancel and lay repeating functions in this trigger:
http://marketfeederpro.com/learn/triggers/best-opposite-price/ 

Hi
Use the Bet Lifetime. Click the little clock next to "Cancel" in the trigger editor. Then Execute your trigger no more often than x secs

ok. I will try it. but will it stop to make bets after one is matched?

Hi
use a condition:
and selections lay matched is equal to 0

Hi
If the soccer games you are betting in are consecutive, like greyhound or horse racing markets, you would use a condition block in your betting trigger:
AND
     trigger <name of your betting trigger> number of runs is equal to 0 overall
     or previous triggered events status is settled
this will make sure the win/lose variables are updated and no new bet will be placed until the previous market is settled.

If you are betting in concurrent markets, then as you point out, the win/lose variables are less useful because you cannot keep track of individual bets. You may be able to set up user variables for the 1 to 10 bets you have, and update those user variables, but that will be a complex trigger.

The better way for you would be to use a maximum bank variable and adjust your staking as and when Betfair updates your account balance. Some examples of this in these topics:
https://community.welldonesoft.com/archive/something-so-simple-has-a-snag-for-loss-recoupment-on-next-bet/msg8348/#msg8348
https://community.welldonesoft.com/marketfeeder-general-discussion/help-with-recoupment/msg12737/#msg12737