Slippy is my biggest no go, Leave aside players for a moment, you also need to think about you. Are you perfectly happy to jog, run, sprint, twist, turn ?
Is the whole pitch a risk. Goal mouths esp hard? is it just a few bits out at corner flag
Are conditions thawing, staying the same, sun coming up, no sign of sun, Is the temp rising or to rise, whats the forecast?
gauge the players and managers behaviour pre match, are you the only one wanting to play? Are they all wanting to play? one team more than other? be eyes and ears, watch their warm up, are they not following through properly kicking the ball for fear of slip? Are team mates passing comment to each other ' this is a joke' etc?
be coy, dont commit early, weigh up everything thats going on, is there a game on the next pitch, hows it going.
" is it on ref", reply with ' touch and go, what are you thinking?"
communicate openly, be open to input,
if you decide to go ahead, each to own but i stay clear of " ask your players to be sensible" etc. You would never not want the players to be sensible! if you have deemed the pitch playable ( safe) then thats that. If you need to ask for a change or mideration to the players intentions, you are contridicting yourself by saying the pitch is playable ( safe)
Setting yourself up for a huge fall when the first dubious tackle comed in!
As referee you either declare the park playable ( safe) or, I think it be ok AS LONG AS....( putting provisos in) , in which case all bets should be off, safety first, no game.
I use terms like " we can all see its one of those touch and go ones, as things stand right now am willing to start if you both are, bear in mind if we start that does not mean we are definately seeing out the 90"
I have very little involvment with captains so at the toss, if we decide to go ahead obv, i prob say something like, " if its obvious i hope i would be aware but if you find your players losing their footing, gimme a shout"
the one thing you will be certain to get if you go ahead, is a dodgy sliding late tackle, to which you be thinking red or yellow, more so red, followed by shouts of " Parks slippy ref, think about the conditions"
easy retort is, " you also need to think about the conditions"
Its a difficult task assessing an orange card at the best of times, you, by your own choice to play the game have made it even harder by adding in the underfoot conditions. Are we willing, or indeed able ability wise, to give ourselves this task?
You then have the fear of one team being three up at half time and conditions are deteriorating. You indeed might be more worried for your own footing, you now have a very difficult sell if deciding to call the game off.
Flip side, you get to 70 mins, with a variation of scores, well, you have got this far, surely you can see it out, weighed up against I really cant, folk are falling over
Bottom line is you are the one taking responsibilty for deeming the pitch playable, if in turn you do end up with the nightmare senario of countless limbs scattered across the pitch, whilst of course its not us made the tackle, or us twisted our ankle in a slip, it is us who have announced
" i as match referee declare this pitch playable today"
If we are going to regret that driving home post match, we already know our decision
edit, please never fall for old wives tales of sticking a car key in the ground to see if its safe and so on. Use the footwear best suited for the conditions, have a selection of footwear avail, be prepared.