Is it necessary to practice bitcoin trading by replaying the market?
There is not much context with this post, and I'm not 100% sure that I can answer correctly, but I think you're referring to technical analysis when you say "replaying" the market. Technical analysis is when you look at the charts, which provide a visual "replay" of what has previously happened within a particular market.
Example: "BTC/USD kraken", whereas "BTC/USD" is the trading pair, and "Kraken" is the exchange. Technical analysis relies on reading the past of candlesticks moving on a chart.
So, to answer your question regarding "
Is it necessary to practice trading by replaying the market?". The answer is yes, replay the market by learning to use technical analysis and observe the past and present, to help make a more rational & logical prediction of the future.
That's a fundamental part of what it means to be a good trader. Study, study, and study some more, because practice makes perfect.
Also don't forget, always remember to practice you're due diligence!