Knowing the weaknesses of your opponents is clearly advantageous. To use a tennis analogy, you might remember Sharapova focusing on Serena William's, relatively, weak forehand to clinch the 2004 Wimbledon final.
But even more valuable can be the ability to recognise an opportunity - think of Nalbandian at Wimbledon 2005, who made the fatigued young Scot, Murray, scamper from one side of the court to the other in to successfully come back from being 2-0 down to win 3-2, or Venus Williams doing the same to Lindsay Davenport in the final to clinch the title.
Opportunities tend to be time-limited. They will not exist forever, appearing and then disappearing, much like the Cheshire cat who Alice wished, "wouldn't keep appearing and vanishing so suddenly", because it was enough to, "make one quite giddy".
One such example occurred in the mid 1980s when ASDA was significantly ahead of Tesco in the UK supermarket wars and then lost a number of its key executives.
Tesco surmised that ASDA would be concentrating on recruitment rather than day-to-day retailing and so decided to launch a concerted campaign (including local billboards and free plastic bags) to exploit this temporary weakness. As a result they pulled ahead and have never looked back.
Two decades on, both Morrisons and ASDA are presenting huge opportunities to their rivals for similar reasons.
ASDA has been diverted by the Walmart connection and all the accompanying over-complications and internal lobbying for power that this has brought about, not to mention a movement of talent to the parent company as well as away from it - like Tony DeNunzio the recently-departed chief executive.
ASDA responded this week by cutting 1,400 (mainly) management jobs and hiring back some old boys and girls. But this will only further confuse ASDA's staff who will now devote a lot of time to trying to figure out who their new boss is and whether their job will be the next to go.
This is good news for recently-beleaguered Sainsbury's who suddenly find that they have the potential to make rapid tactical and strategic moves that will past unnoticed by distracted ASDA employees (or "colleagues", as they now call each other).
Morrisons presents even more of an opportunity because of the complete mess that they have managed to make with their misguided, crude attempt to buy growth by acquiring a failing rival, Safeway, that they knew (and know) nothing about.
Morribobs (as they are known in the North) are plain, straightforward, stereotypical Yorkshire men. They know their customers and how to give them the ugly, inexpensive, easy to walk to, supermarket shopping experience that they are willing to tolerate (if not exactly crave).
They used to have a global reputation for reliability of profits - but that was before they bought a company whose customers and aspirations are almost diametrically the opposite of their own.
So while there was no overlap of store locations, someone forgot to take into account that there was also virtually no overlap of skills, culture, knowledge or accounting practices. Good news again for Sainsbury's.
Elsewhere, the purchase of MBNA – a huge credit card issuer who have doubtless sent you pre-approved offers in the post – by Bank of America (for $35 billion) will present a big opportunity to Capital One, MBNA's chief rival and nemesis.
Both target essentially the same sector and market, but now MBNA will be paralysed by post-acquisition activities and meddling. If it's competitors push forward hard, they will gain market share. If they wait, they risk being blown apart by the new stronger, better-equipped mother of all credit card issuing death stars. But for the moment at least, opportunity knocks.
On a much bigger scale, an opportunity also exists to turn Africa into a 'New China' that is bound to the UK (and even Europe) in a new kind of special relationship. Forget trying to forge a consensus with the United States. Their trepidation is our chance.
There are stable Africa states that just need the three step package proposed by people like Jeffrey Sachs and Nobel Prize-winning economist, Joseph Stiglitz,. This consists of Debt Relief, Aid to Educate and Alleviate Extreme Poverty, and, most importantly, a revision of trade that allows Africa (and other developing countries) to trade on equal terms with the West.
With these in place, Africa could follow the gradual capitalism of East Asia and India to move into manufacturing and service industries with the benefit of English and French-speaking populations and low labour costs.
If we help them, we benefit. It will become not charity, or even morality, but the best course we could follow in our own self-interest. Adam Smith's invisible hand would, indeed, guide us if we can just ensure that we take our own hands away from our eyes and see the opportunity for what it really is.
