This week’s puzzle marks the opening round of a national competition in which Guardian readers have performed with notable success over the years. The annual Winton Capital British Solving Championship for 2014, open to any British resident, has a sharply boosted £2,000 prize fund, with free entry and just a single move answer which you can send by post or email.

You have to work out how White, playing as usual up the board, can force checkmate in two moves, however Black defends.

To enter, simply send White’s first move to Steve Giddins, 4 Fennel Close, Rochester, Kent ME1 1LW. Alternatively, you can email your first move to winton@theproblemist.org. Either way, mark your entry “Guardian”.

The closing date is 14 August. After that, all entrants will receive the starter problem answer and those who get it right will also be sent a postal round of eight problems, with plenty of time for solving. The best 25-30 entries from the postal round will qualify for the one-day national final, to be staged at Eton college in February 2015.

The final will qualify winners for the European and world individual and team solving championships to be staged later in 2015. In the decade since Winton Capital launched its sponsorship backing, British solvers have won both team and individual medals in these events, and are currently ranked among the top nations behind Poland.

The starter puzzle may seem tricky due to the crowded board and the apparently wide variety of choice for White, but bear in mind that composed problems hardly ever have checking or capture first moves, while implausible choices that offer Black extra defences are often candidates for the answer.

At worst, you can find the true solution by trial and error. Good luck to all Guardian entrants, and be sure to double check your answer.

England will field five 2600+ grandmasters led by Michael Adams in the 180-nation world team Olympiad at Tromso, Norway, in August. Russia will be No1 seeds and the world champion, Magnus Carlsen, will play for the hosts. England women include Akshaya Kalaiyalathan,13, of Nonsuch School, Surrey, who tied for the 2013 British women’s title.