What BTC rate are you using. If you calculate the ROI at a BTC rate of $10500 giving you a daily payout for each S9 at ~$23 would give a significantly different comparison at $16500 BTC rate and a daily payout for each S9 at ~$45.
I'm using whattomine. I believe the price was $10,500 on whattomine when I posted
Yes, I do understand, my original numbers were posted at Higher BTC rates:
Jan 22, 2018 11,288.0
Jan 21, 2018 11,514.0
Jan 20, 2018 12,728.0
Jan 19, 2018 11,207.00
Jan 18, 2018 11,045.00
Jan 17, 2018 11,082.00
Jan 16, 2018 11,072.00
Jan 15, 2018 13,575.00
Jan 14, 2018 13,558.00
Jan 13, 2018 14,191.00
Jan 12, 2018 13,783.00
Jan 11, 2018 13,266.00
Jan 10, 2018 14,896.00 I started this Post on this date
Jan 09, 2018 14,423.00
Jan 08, 2018 14,930.00
Jan 07, 2018 16,196.00
Jan 06, 2018 17,161.00