We always (if you play this Dota 2 games) see player type "-ping" beginning of the game, or during waiting all player connected. The main reason is they want to check ping and packet lost. High ping will result delay in game. For me below 100ms considered OK.
Well you don't have to type it anymore, make it permanently displayed. But you need to adjust where the number will display - top, bottom, middle or top-right. Its your choice..
1st of all you need to enable the console. The steps:
Open Steam client > Library > Right click Dota 2 > Properties > Click Set Launch Options > Type -console > OK > Close
Now start the Dota 2 games.
You'll see the console after you entering the games. Now now on, just click ~ button to open the console. (just like conter strike game..LoL)
Ok, now type "net_graph 1". 1 here mean you enable the counter thing. You'll see it right away. You may config it here or in game. Advisedly, create any game from lobby and config or replace it according your in game preference. So that you got some view which exactly you want to put it.
There in game view (top pic). So some other net_graph setting are:
net_graphheight