SCENARIOS - Outcomes for the Afghan presidential run-off

By Golnar Motevalli

KABUL (Reuters) - Afghans vote on Nov. 7 for a second time in their disputed presidential election, hoping to end weeks of political limbo and uncertainty.

President Hamid Karzai -- who agreed to the run-off after diplomatic pressure following a U.N.-backed fraud investigation into the first round, which tossed out hundreds of thousands of his votes -- faces former foreign minister Abdullah Abdullah.

Given the first round fraud allegations, the run-off's legitimacy and fairness will be important to Washington's policy on Afghanistan, including a decision by U.S. President Barack Obama on whether to send more troops.

Here are some possible scenarios for the outcome:

KARZAI WINS SECOND ROUND

Analysts and even U.S. Secretary of State Hillary Clinton have said Karzai is likely to win, because as a Pashtun -- Afghanistan's largest ethnic group -- he has grassroots support in the south and east. Many Afghans see Karzai as experienced and believe he is best placed to achieve a degree of stability.

The U.N. fraud probe brought Karzai's votes in the first round down to under the 50 percent needed for an outright win, but well ahead of Abdullah.