This addon allows you to play counter-strike 1.6 singleplayer forever, courtesy of Z-Bot Dev team. I Included a Script Runtime that allows you to run-once, and scramble all of your maps in the load order of maps, so you never get the same maplist twice.
Install should point to your:
C:\Program Files (x86)\Steam\steamapps\common\Half-Life\
This will Install CS 1.6 Z-Bot (Fully Functional)
CS Map Scrambler Runtime (Run Once from Desktop Shortcut to Randomize Map Load Order)
bot_addbot - Adds a bot to any team
bot_kill - Kills all Active Bots
bot_kick - Kicks all bots from server