The way that train lengths are decided is a little bizzare to me. I tend to travel in early and get home early, but occassionally have to travel in peak time and more often than not the trains are 6 carriages during the peak.

On my normal commute the 07:00 is 8 carriages and I always get a seat at FH, and most people do all the way to LB. Coming home again its a bit strange. I sometimes get the 16:15 to Guildford which is 4 carriages and normally pretty full, but if I miss that I catch the 16:24 to Victoria which is 6 carriages and empty