Last week’s BTG Newsletter started with the provocative observation that “One of our reviews this week begins by asking a potentially dangerous question: 'what is the point of theatre critics?'”

A glib answer might be that if theatre critics had no point, there would be no need for our publication (or those of dozens of competitors), which has been running for 20 years and is still going strong.

To add to the controversy, one of the world’s leading film actresses Viola Davis reacted badly to negative reviews of her latest venture The First Lady by stating that “critics absolutely serve no purpose”.

BTG Editor David Chadderton when looking for a suitable riposte proposed that “one of the most satisfying from my point of view is the chance to give a boost to an artist, company or production that hasn't yet achieved the prominence they deserve and may otherwise have slipped under the radar.”

While discovering and promoting a hitherto hidden talent is undoubtedly very pleasing, there are many more reasons why theatre criticism has existed for the last several hundred years and will almost certainly continue to do so into the foreseeable future.

Before getting into that, it may be necessary to define terms in a world where everybody is encouraged to have his or her own blogging opinion, however untrained or misguided.

Theatre criticism is something far greater than a typical early teen response to their first visit to Shakespeare “I hated that—it was boring”. Unfortunately, many but by no means all bloggers apply exactly the same negligible critical faculties to a sublime production at the National Theatre as they do to a McDonald’s cheeseburger or new pair of throwaway shoes.

Having lectured on this topic to theatre students over the years and received cogent and intelligent feedback, this particular critic has concluded that the artform has value in several different ways. Perhaps the most valuable, in a literal sense, is the assistance that we can provide when someone wishes to enjoy a night out at the theatre and needs help in choosing a production that will delight.

Nowadays, a pair of tickets to a top West End show can cost several hundred pounds. If you get it wrong, then this money is wasted and so is what should have been a wonderful night out.

The best critics, like most of those on BTG, have been watching and reviewing plays for decades. Over time, their judgement has been proven to be accurate on the vast majority of occasions, primarily because they along with other dedicated experts in the field agree on the merits of most shows that they review. This means that the odds of getting it right by following the opinions of a respected critic are far greater than those if one relies entirely on tweets from random theatregoers.

Looked at from a very different perspective, the best theatre critics write copy that is an art in itself. Many will have derived great pleasure from reading collected reviews by the likes of Kenneth Tynan or Michael Billington, even though they may not have watched the productions and performances under the microscope. Because they have seen so much over the years, critics are also able to compare and contrast different ways of interpreting classics and bringing new work to the stage.

Using a different comparison, if you wanted to buy a motorboat, you wouldn’t base your acquisition criteria on the opinions of seasick landlubbers lambasting the colour scheme or, perish the thought, the physical attributes of size 0 models used to market the vessels. Instead, you would be well advised to read either the views of other owners or perhaps those involved in motorboat construction.

Critics are also capable of drawing together all of the different elements of theatrical productions. Not only will they be able to provide a succinct summary and analysis of plotlines but also comment on what directors bring to the party, the abilities of the actors, rather than merely their renown, and other factors such as the look and feel.

While many of those on the other side of the curtain may be wary of critics, there is also at least a chance that the best of us will make the kind of suggestions that could help performers or backstage crew to at least consider if not necessarily change and improve their work.

It is by no means always the case but often creatives are obliged to work in trying conditions against the clock and it can be helpful to have somebody on the outside delivering a neutral opinion.

One must sympathise with Viola Davis, who feels hurt by negative criticism. The question is whether it is justified. Where a whole slew of critics come to the same conclusion, she might have to accept that they are right.

On the other hand, crass negativity rarely helps anybody, though on rare occasions it can be useful to deter those who might otherwise have wasted money and time watching something truly awful.

In conclusion, please keep reading reviews on BTG. They are independent, generally thoughtful and for the most part, look to find the positives, while identifying relevant shortcomings.