Ok, this is a shout out to all the speed-challenged runners out there. I'm running Chicago in 3 weeks and still don't have the best idea as far as a time goal. Can anyone look at some of my stats below and see if they were anything like what you have run and help me predict a finish time?

I ran 18 miles at 12:01 pace 2 weeks ago.
I ran 21 miles this morning at 12:30 pace.

It poured and was around 75 for my 18 miler, today it was 80-85 with pretty high humidity during my 21 miler.

I live in Houston...that should be enough said about weather on the rest of my runs.

I did 8 Yasso 800s the week before last averaging 4:34 for each (slowest was around 4:43 and fastest was 4:14)...I know not exactly the right way to do them, but most were around 4:40 and we just wanted to "have fun" on the last one. I will do another Yasso 800 workout this Tuesday aiming at a 4:40 time for each 800, and will do 10 repeats.

My previous marathon PR is 5:12 last January. This will be my 9th go at the distance or similar (I've done 5 marathons (5:12-5:55), 2 50ks, and 1 ironman in the past 3-4 years).

Any stabs? Before the Houston marathon in January we have a series of warmup races (half marathon, 25k, 30k), so we have a decent way to monitor our race times and predict our marathon time. This time there is nothing like that for us to do before Chicago (they barely even have any 10k's here between April and October...just too hot).

I think we have decided to start with the 4:45 pace group and see how it goes...does that sound about right, or too fast? I've been aiming for the elusive under 5 hour marathon since my first go and it just never seems to come together for me. This time around I have trained far better and more honestly than for any other marathon.

Thanks in advance!!