Recently Played Anomaly

[simoncn]

The present approach is simple and reliable although it can sometimes result in false positives. To do as you suggest could create false negatives where a track is less than 30 seconds long or when a track is deliberately played and stopped after less than 30 seconds for some reason. Also, some people might be OK with 30 seconds and some might want a longer or shorter cut-off. On balance I think the present simple approach is best.