How many times do I have to kill a player before I am dominating them

As a spy, you're best off spending your time working to assassinate the opposing medic. Since the other team has only one medic, it is a huge advantage to your team if you can kill (or badly hurt) the other medic, even at the expense of your own life.

Since this is a competition-level play, you can expect full communication from the other team. You will very rarely fool them into thinking you're on their team. They all should know where everybody is. (Whether or not they really do is another matter). The simplest way for you to be effective is to find a nice sport to Cloak and Dagger, wait for the enemy medic to run by, and revolver or ambassador them from a distance.

Mix up your spots, be unpredictable, and stay hidden. You may also want to spend some time hounding the enemy sniper, depending on his skill level. I've seen highlander teams completely fall apart from a skilled enemy sniper. On the off chance he's razorbacking, the ambassador will be the weapon you want to go with. Mix your disguises, but definitely use the sniper disguise - that class matches closest with this play-style.

Here is an instruction on how to create a server and put bots on it:

1. Make sure you have the port 27015 accessible for connections.
   ^{How? Look here.}
2. Open the game console.
   ^{How? Options⇨Keyboard⇨Advanced...⇨Enable developer console. Press ~ / ` to open the console at any time.}
3. Type sv_lan 0 if you want the game to be public, or sv_lan 1 for LAN only.
   ^{Public server is recommended}
4. Type map <mapname>, replacing <mapname> with the name of the map you want to play.
   ^{Or press the [+] to the right of BROWSE SERVERS in main menu instead.}
5. If the server is public and you don't want anyone to intrude, you can set a password:
   Type sv_password <pass>, replacing <pass> with some simple password.
   _{(e.g. sv_password 1234)}
6. Set the bot difficulty: tf_bot_difficulty <x>, where <x> is from 0 (the easiest) to 3.
   ^{(e.g. tf_bot_difficulty 0)}
7. Add bots: tf_bot_add <team> <class>
   <team>: red | blue
   <class>: scout | soldier | pyro | demoman | heavyweapons | engineer | medic | sniper | spy
   ^{(e.g. tf_bot_add blue heavyweapons)}
   To remove all bots: tf_bot_kick all

Here are some ways for your friend to connect. If one fails, try the next one.

• Join the game via Steam.
  ^{In Steam Friends list press ▼ and Join Game.}
• In console: connect <ip>:27015, where <ip> is your (server's) IP address.
  ^{(e.g. connect 11.22.33.44:27015)}
• Try the same thing with your (server's) local IP address (find it in Windows/Linux)

If nothing works, see the step 1 of server creation instruction.