This shows SHIT35 in 3 modes:
TOP: the average instant ROC of the 35 Binance alt/BTC pairs in the index against the chart's BTCUSD symbol's instant ROC.
MIDDLE: the correlation between the index's average ROC for the alt/BTC pairs and the chart's ROC.
BOTTOM: the cumulative sum of the index's alt/BTC pairs ROC.
Note how the middle SHIT35 shows that for most of 2018 when BTC was in a downtrend, alt/BTC pairs correlated with it, whereas when BTC started picking up steam in 2019, alt/BTC pairs began to de-correlate with BTCUSD, since alt/BTC pairs have been in a pretty steady downtrend since the 2017 bubble.
The same study could have been made using alt/USDT pairs.