Why is the conditional (highlighted in the code below) detecting a match for values that are NOT defined in the initalized 2d array ....?

//initialization
int validtracks[17][2] = {{1,1}, {1,3}, {1,6},{2,3},{2,6},{3,4},{3,6},{3,8}, 
{4,2},{4,3},{4,7},{5,3},{5,5},{6,1}, {6,3},{7,1},{7,3}};


//main code
while (matchtrack == 0) 
{
     rndint = rand() % 7 + 1;

     for (int r = 1; r < 18; r++)
        {

        if (validtracks[r][2] == rndint && validtracks[r][1] ==   
            rndtracks[1] && matchtrack == 0)
             {
             matchtrack = 1;
              }

        }
}

What I have tried:

I have narrowed the problem down to the conditional:

if (validtracks[r][2] == rndint && validtracks[r][1] ==rndtracks[1] && matchtrack ==0)
            {
            matchtrack = 1;
            }


For some reason it's detecting a match with elements in the array, when it shouldn't be:
//initialized array
int validtracks[17][2] = {{1,1}, {1,3}, {1,6},{2,3},{2,6},{3,4},{3,6},{3,8}, 
{4,2},{4,3},{4,7},{5,3},{5,5},{6,1}, {6,3},{7,1},{7,3}};