Nick Hood is senior London partner at business rescue specialists Begbies Traynor.

It's a fairly familiar story when a star from a large accountancy practice decides to join a smaller one, either to see out the tail end of their career or to avoid a career roadblock. But after the initial blaze of publicity, there is little coverage of the outcome and interested observers struggle to find out if the appointment has worked out for both parties.

Assimilating a big hitting partner into a much smaller practice is a classic case of easier said than done. That's not to say that it's impossible, because sometimes it does work out well. But the odds are against a happy ending.

The big hitter uses their skills and diplomacy to charm their new colleagues, and because they have always worked alongside highly ambitious colleagues, their professional DNA still carries the fire and passion for continued success.

But sadly, more often than not, this sort of appointment fails to live up to people's high expectations. In a career spanning over 40 years, time and again I've witnessed the failure of the big hitter to make a positive contribution when they join a smaller accountancy practice.

Note the careful use of the word positive. Far too frequently, the former star from the well-known partnership arrives with a bang and exits with a whimper, having failed miserably to bring in the new clients and boost profits in the way they were expected to.

Why is it that in too many instances the big hitter's arrival does more harm than good? The answers vary but there is usually a series of common causes.

A classic mistake is the tendency to put too much confidence in the brand name from where the superstar comes. This person may have enjoyed a successful career working for the Big Four, but this is no guarantee that they can prosper in the very different world of the smaller firm, no matter how bright and professionally-skilled.

Often, the smaller practice doing the hiring has failed to find out about the hitter's personal contribution before bringing them in. Did their due diligence reveal if they were really instrumental in their previous firm's success or whether they were just a figurehead with a gift for self-publicity? Or was it that they were under-pinned by talented colleagues, any one of whom might have been a better choice?

Did the smaller practice work hard enough to establish if the hitter is still hungry for success? It may well be that in their later years they were just coasting along, or playing a devious political game in their rise to the top, deliberately riding on others' coat-tails while climbing the career ladder.

Sadly, distinguishing between the real achiever and the myth is no easy feat. These people interview extremely well and very few people feel able to provide warts 'n' all references, even when asked to provide discreet feedback. In today's HR world, you should expect to get only the blandest of responses.

Bearing this in mind, answers should be interpreted carefully. If soundings produce very anodyne comments from the hitter's current colleagues, this should ring alarm bells. Normally people love to give effusive and positive remarks; therefore any reticence or obvious 'holding back' should be treated with some concern. If there is even a slight doubt, err on the side of caution. The real possibility exists that these diplomatic comments and very factual answers belie the story they would really like to tell.

Invest time in speaking to as many people in the broader market as possible, not just the accounting world itself. If possible, see if you can talk to the candidate's clients. The advantage of this approach is that these people may feel freer to speak, and what they have to say may be a better indicator of the big hitter's real performance.

A surprisingly common misjudgment is to treat the hiring process as more of a social event, to be done over cosy dinners and with normal HR processes cast to one side. Given the social skills of many of these candidates, the chances are that the discussions will be dominated by them in a dangerous game of role reversal.

But remember, recruiting the right person is more about how they will fit into a current organisation than how they fitted into the practice they are seeking to leave.

Inevitably, large practices require employees to fulfil more specialist roles, while smaller ones need their people to be much more rounded. For example, do your existing partners and managers do their own paperwork and administration? Also, do they do their own marketing? Will your big hitter be prepared to be similarly self-supporting?

If they demand that you also hire their current secretary or PA, ask yourself what effect this will have on their new colleagues who currently look after themselves. In my experience, if the privileges offered to a big hitter are too generous the bitterness this stokes up will be counterproductive.

Also, if your new star has never worked for a smaller practice, be cautious about their flexibility. Adapting to new circumstances is easier when younger, and they may have reached an age when their work habits are too ingrained to be easily changed.

It may well turn out that your big hitter is a pragmatist who is willing to accept an interesting new job that swaps perks and status for the thrill of a genuine challenge. Home and dry? Not by a long way.

For all their best intentions, big hitters can be surprisingly naive.

Coming from such a protected professional environment, they fail to appreciate just how difficult it will be to adapt to a smaller organisation.

They may have no real experience in a smaller practice, of having to beg, steal or borrow resources to get results, or if all else fails, simply do it themselves. At their previous firm they had the resources at their disposal to handle the detail. And before long they become dispirited when they realise that many of their best contacts have secretly crossed their name off their lists because they can no longer dispense those big firm favours like taking them to fine restaurants or upmarket events.

In a matter of months, the honeymoon period is well and truly over. New colleagues have come to realise that the big hitter is no better at the job than themselves, yet sense that they are on a much higher package.

Unconsciously, they cease to extend their goodwill. Our star is left abandoned trying to work the copier or trouble-shoot an IT problem, and their effectiveness is in steep decline.

This isn't a pleasant scenario, but how often have you seen it played out at your practice or one of your competitors? Probably more than you'd like to think.

Hiring a big hitter comes with plenty of risks. It is good on paper but often disappointing in reality. A better alternative may be to look for new staff who have succeeded in other smaller firms. If these people have achieved proven results by working for practices that most haven't heard of, they are probably the most talented and hard working staff. And your practice doesn't have to lose face by dispensing with the fallen star who failed to light up the professional sky for you.