Nov 2015 - last peak of BTC dominance Aug 2016 - halving 2016 Jan 2018 - last dip of BTC dominance Aug 2019 - 4 years minus 3 months(halving offset) from the last peak of BTC dominance(which is potentially the current peak of 70% BTC dominance) Nov 2019 - 4 years percisely from the last peak of BTC dominance May 2020 - halving 2020
2nd leg of decline could be just across the corner