Your right there Kenny. Track bias is an overused description applied far too often to a situation that usually just isn't there ['overlay' is another word similarly overused and misunderstood].

When Oliver walks a track with his metal prod zig-zagging at 45% angles around a track he is looking for the firm going that may or may not exist at various track sections. One whole section may be firmer on the inside and another in the centre etc. What he is looking for is the firm ground which he can use to his advantage. This would be called a 'track bias'. Everything else is track layout and is also to be considered [differently] for various race distances.

Track bias is a hotly contested topic and my opinion above is only that.