First and second partially collapsed metric values are determined for each bit in a symbol transition. Each first partially collapsed metric value is a cumulative metric of starting in a first state and ending in a second state in L transitions with the respective bit in the symbol transition being a first value. Each second partially collapsed metric value is a cumulative metric of starting in the first state and ending in the second state in L transitions with the respective bit in the symbol transition being a second value, the second value differing from the first value. For each bit in the symbol transition, a relative likelihood value is determined based on its respective first and second partially collapsed metric values. A symbol is decoded based on a hard decision performed using the relative likelihood value for each bit in the symbol transition.