Hi
Several ideas:
Price is king - I would set a minimum target price for the greenup trigger to fire. e.g. assuming a back bet, r_ticks(bm_backp, -10) and ask for r_ticks(bm_backp, -15)
or if you want to guarantee a match r_ticks(bm_backp, -5).
You could use a combo of price and what mcbee suggested above.
Another more complex approach would be to correlate prices in another market, which may be more accurate than relying on market_score
e.g. if back_price for 0-0 in correct score is > 500 the first goal has been scored
Also have a look at “Market’s Score Has Changed” as a condition
Finally, there is some material on the forum on how to set a delay by using a counter, or by comparison with now_time or Current Time