Alex de Vries, a blockchain specialist at "Big Four" consultancy firm PwC and founder of crypto analytics site Digiconomist, has said that 98% of bitcoin mining machines will fail to produce a block of transactions during their average lifetime of 1.5 years. Around 4 million machines are currently active and nearly 75,000 blocks are produced every 1.5 years – meaning less than 2% machines are able to produce a block to verify bitcoin transactions, de Vries tweeted Monday. The remaining 98% of machines never produce any blocks, he contended. "The lifetime of course varies, but if you look historically, you do see ... (full story)